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RESEARCHES,
CHEMICAL AND PHILOSOPHICAL ;
CHIEFLY COXCERSING
NITROUS OXIDE,
OR
DEPHLOGISTICATED NITROUS AIR,
AND 1X3
RESPIRATION.
By HUMPHRY DAVT,
SUPERJNTEXDEXT OF THE MEDICAL PNEUMATIC
IXSTITUnON.
LONDON:
FUITTED FOR J. JCfHKSOX, ST. PAUL's CHUECH-YARP.
»Y BIGGS AND COTTLE, BRISTOU
i9oa.
y<r/z
xi.
CONTENTS,
Introduction,
RESEARCH I.
I^lo the analyfis of x\t,tric Acid and Nitrous Gas,
and the produdiion o/-Nitkous Oxide.
DIVISION I.
ExPERmENTs and Observations on the compofuion
of Nitric Acid, and on its combinations nvith
Avater dfW Nitrous Gas.
1. Preliminaries - _ _
2. Produdion of aeriform Nitrous Acid - \ \
3. Specific gravity of Gafes " - - 6
4. Experiment on the formation of Nitrous Acid "^ 1 1
5. Conclufions - ^ _
6. Experiments on the combinatfon of >fitrous Gas with ^^
Nitric Acid . _
7. Additional Experiments - . " ^^
8. Conclufions . _
£>: Mr Thomson's The6ty of the difference between ^^
JNitnc and Nitrous Acid
10. Compofition of the different Nitrous Acids - sg
1 1 . Combination of Nitric Acid with Water . «
J2. Of Nitrous Vapor - . ^^
'3. Comparifonoftherefults^withthofe of Cavendiih ^^
and Lavoifier
4^
( iV. )
DIVISION XL
Experiments and Observations on the compofition
of Ammoniac and on its combinations with Water
and Nitric Acid.
1 . Analyfis of Ammoniac - - _ 5^
2. Specific gravity of Ammoniac - - 62
3. Of the quantities of true Ammoniac in Ammoniacal
Solutions - - - - 65
4-. Compofition of Nitrate of Ammoniac - 7^
5. Decompofitionof Carbonate of Ammoniac, by Nitrous
Acid _ - _ - - 75
5. Decompofition of Sulphate of Ammoniac by Nitre 77
6. Non-exiflence of Ammoniacal Nitrites - 79
7. Sources of error in Analyfis - - 8Q
8- Lofs in Solutions of Nitrate of Ammoniac daring-
evaporation - - - - 83
DIVISION III.
Decomposition of Nitrate of Ammoniac — Prepara-
ration of respirable Nitrous Oxide,
1. Of the heat required for the decompofition of Nitrate
of Ammoniac - - - - 84
2. Decompofition of Nitrate of Ammoniac — Produdion
of refpirable Niti'ous Oxide- — its properties - 86
3. Of the Gas remaining after the abforption of Nitrous
Oxide by Water - - - - 89
4. Specific Gravity of Nitrous Oxide - - 94
5. Analyfis of Nitrous Oxide . - - - 95
6. Minute examination of the decompofition of Nitrate
of Ammoniac - - - - 101
7. Of the heat produced during the decompofition of
Nitrate of Ainmoniac - - - lOS
( V. )
58. Dccompofition of Nitrate of Ammonfac at high tem-
peratures - - - . log
^. Speculations on the deccvnpolitions of Nitrate of
Ammoniac - - - ~ 113
JO. Of the preparation of Nitrous Oxide for experiments
on refpiration - »- - - II7
DIVISION IV.
Experiments and Observations on th,e conopolition of
Nitrous Gas^ and on its abforption by different bodies.
1. PreHminaries - _ _ - 122
2. Analylis of Nitrous Gas by Charcoal - 126
3. Analylis of Nitrous Gas by Pyrophorus - 132
4. Additional obfervatioiis on the compolitipn of Nitrous
Gas - - - - - 134
5. Abforption of Nitrous Gas by Water - 14,0
jd. Abforption of Nitrotis Gas by Water of different kinds 14/
7. Abforption of Nitrous Gas by iflution of pale gfeen
Sulphate of Iron - _ _ 152
8. Abforption of Nitrous Gas by folution of green mti-
riate of Iron - - - - 179
9. By Solution of Nitrate of Iron - - 1.87
10. By other metallic .Solutions
1 1 Action of fulphurated Hydrogene on folution of green
fulphate of iron impregnated with Nitrous Gas. 19I
12. Additional Obfervations - - - 193
DIVISION V.
JlxrERiMENTs and Observations on the produ6tion of
Nitrous Oxide from Nitrous Gas and Nitric
Acid in different modes.
1. Preliminaries - - - - 1^7
2. Converlion of Nitrous Gas into Nitrous Oxide by
alkaline fulphitee - , ^ * I99
< vi. )
3. By Muriate of Tin - - - - 202
4. By Sulphurated Hydrogene - - . 203
5. Decompolition of Nitrous Gas by Nafc^it Hydro-
gene - - - - - - 206
6. Mifcellaneous Obfervations - - - - 209
7. Recapitulation - - - --211
8. Piodu^tion of Nitrous Oxide from Metallic Solutions 213
g. Additional Obfervations relating to the produtlion of
Nitrous Oxide - - - ^ 2K)
K) Decompofition of Aqua regia by platina, and evolu-
tion of a gas analogous to oxygenated muriatic acid,
and nitrogene . _ _ _ 223
11. Adion of the eledric fpark on a mixture of Nitro-
gerpe and Nitrous gas . . _ 22(j^
12. General remarks on the production of Nitrous Oxide 23 1
RESEARCH II.
Into the comhlnations o/'NiTROUS Oxide, and its deci,ni-
^ojition.
DIVISION I.
Experiments and Observations on tfie combinations
of Nitrous Oxide.
1. Combination of Water witli Nitrous Oxide - 235
2. of Nitrous Oxide M^ith fluid inflamma-
ble bodies. _ _ . » 240
3. A6tion of fluid Acids on Nitrous Oxide - 244
4. ' of Saline Solutions - - 245
5. of Gales - - . . 248
6. A6tion of aeriform Nitrous Oxide on the alkalies —
Hiftory of the difcovery of the combinations of
Nitrous Oxide, with the alkalies - 254
7. Combination of Nitrous Oxide with Potafh - 262
( vii. )
3. Combination of Nitrous Oxide with Soda - 268
9. ■ — ■■ with Ammoniac 269
10. Probability of forming compounds of Nitrous Oxide
and the alkaline earths - - 273
11 Additional Obfervations - - 274
12 The properties of Nitrous oxide refemblethofeof Acids27<5
DIVISION II.
Pecompolition of Nitrous Oxide by combuftible
Bodies. I
1 Preliminaries - - - - 278
2 Converlion of Nitrous Oxide into Nitrous Acid and
a gas analogous to Atmofpheric Air by ignition 279
3 Decompoiition of Nitrous Oxide by Hydrogene 286
4 ' " by Phofphorus 293
5 • by Phofphorated Hydrogene 300
6 by Sulphur - 303
7 by Sulphurated Hydrogene 8O6
8 by Charcoal - 311
9 by Hydrocarbon ate - 313
10 Combuftion of Iron in Nitrous Oxide - 3l6
11 of Pyrophorus - - 318
12 , — of the Taper - - 319
13 of different Compound Bodies - 321
14 General Conclufions relating to the decompoiition
of Nitrous Oxide, and to its analyfis - 322
15 Obfervations on the combinations of Oxygene and
Nitrogene - - - ^ - 325
RESEARCH III.
Meluihig io the KfiSPiBATioN 0/ Nitrous Oxide and
OTHER Gases.
f viii. )
DIVISION I.
Experiments and Observations on the efFe(9:s pro-
duced upon Arjimals by the refpiration of Nitrous
Oxide.
1 Prehminaries - > - - - 333
2 On the refp nation of Nitrous Oxide by warm-blooded
Animals - - - - - 830
3. EfFe6ls of the refpiration of Nitrous Oxide upon
Animals, as compared with thole produced by their
immerfion in Hydrogene and Water - 343
4. Of the changes efFeded in the organifation of warm
blooded Animals, by the reijpiration Of Nitrous-
Oxide - - - - 347
5s Of the refpiration of mixtures of Nitrous Oxide and
other Gafes, by warm-blooded Animals - 358
6. Recapitulation of fa6ts relating to the refpiration of
Nitrous Oiiide, by warm-blooded Animals - 360
7. Of the refpiration of Nitrous Oxide, by amphibious
Animals - - - - 362
8. Effeds of Solution of Nitrous Oxide on Filhes - 366
9. Effects of Nitrotis Oxide on Infeds - - 3/0
DIVISION II.
Of the changes efFefted in Nitrous Oxide and other
Gafes, by the Refpiration of Animals.
1. Preliminaries _ _ _ _ 373
2- Abforption of Nitrous Oxide by Venous Blood 374
3. Of the changes effcded in Nitrous Oxide by Refpi-
ration .... 388
4. Refpiration of Hydrogene - - 400
5. Additional Obfervations and Experiment? on t|ie
Refpiration of Nitrous Oxide - - /J|4
( i^^. )
6. Of the Refpiration of Atmofpheric Air - 42p
7 . Refpiration of Oxygene - - - 439
8. Obfervations on the changes effected in the blood by
Atmofpheric Air and Oxygene - - 445
g. Obfervations on the Refpiration of Nitrous Oxi,de 440
RESEARCH IV.
Belating to the Effects produced by the Respiration of
Nitrous Oxide upon different Individuals.
DIVISION I.
History of tJie Difcovery. — Effects produced by the
Refpiration of different Gases.
1. Refpirability of Nitrous Oxide - - A5Q
2. Effeas of Nitrous Oxide - - - 453
3. General Elfe6ts of Nitrous Oxide on the Health 464
4. Refpiration of Hydrogene - - - 4^0
5. ofNitrogene m ^ - 467
6. EfFefts of Hydrocarbonate - - 463
7. — of Carbonic Acid - - 4/2
8. — of Oxygene ' - - _ 4^3
9. — of Nitrous Gas - . - - 4/5
iO. Mofl exteniive action of Nitrous Oxide produces
no debility - _ _ _ 4c^5
DIVISION If.
Details of the Eife6ts produced by the Refpiration of
Nitrous Oxide upon ditferent Individuals, furnifhcd
'by Themfelves.
1 Detail of Mr. J. W. Tobiu - - 4(}7
2 — of Mr. W. Clayfitld > - ' 5Q;2
3 Letter from Dr. Kinglake - - 503
4 Detail of Mr. Southey - - - jO;
( X. )
S Letter from Dr. Roget - - - 50g
fi Letter from Mr, James Thomfon - - 512
7 Detail of Mr. Coleridge - - > 5l6
8 — of Mr. Wedgwood - - - 518
9 — of Mr. G. Burnet - - - 520
ao — of I>Ir. T. Pople . - - 521
11 — ofMr.Hammiek - - . 522
12 — of Dr. Blake - - - - 524
13 — of Mr. Wanfey . - - 525
14 — of Mr. Rickman - - - 526
15 — of Mr. Lovell Edgworth - - 527
16— ofMr. G.Bedford - - - 528
17 — of Mifs Rylaiid . , - 530
18 Letter ffom Mr. M. M. Coates - - 530
DIVISION III.
Abftrads from additional Details — Obfervatlonson the cfFe6ts
of Nitrous Oxide, by Dr. Beddoes — Conclufion,
1 Abllra^ls from additional details - - 533
2 Of the effects of Nitrous Oxide on delicate females 5:^7
^ Obfervations on the effe6ts of Nitrous Oxide by Dr.
Beddoes. ----- 541
4 Conclufio|i ----- 54^
APPENDIX.
No. I. Of the effeds of Nitrous Oxide on Vegetables 56l
No. II. Tabic of the Weight and Compolition of the
combinations of Nitrogene _ - - 50(5
No. III. Additional Obfei-vations - - - 56/
No. IV. Dcfcription of a Mercurial Airholder, and
Breathing Machine, by Mr. W. Clayfield.
No. V. Propofals for the Prefervation of Accidental
Obfervations in Medicine. By Dr. Beddoes.
INTRODUCTION.
Xn confequence of the difcovery of the ret'-
pirabiiity and extraordinary effe61s of nitrous
pxide, or the dephlogifticated nitrous gas of
'Dr. Prieftley, made in April 1799, in a manner
to be particularly defcribed hereafter, * I was
induced to carry on the following inveftjgation
concerning its compofition, properties, combi-
nations, and mode of operation on living beings.
In thecourfe of this inveitigation, I have met
with many difficulties ; fome arifing from the
novel and obfcure nature of the fabjed, and
* A (liort accQunt of this difcovery has been given ia Dr.
Eeddoes's Notice of fome Obfervations made at the Pneu-
matic Inftitution, and in Mr. Nicholfon's Phil. Journal for
May and December 17 9Q,
( xii. )
others from a want of coincidence in the obfer-
vations of different experimentalifts on the
properties and mode of produdion of the gas.
By extending my refearches to the different
fiibftancesconnedled with nitrous oxide; nitroiisj
acid, nitrous gas and ammoniac ; and by mul-
tiplying the companions of facfls, I have fuc-
Geeded in removing the greater number of
thofe difficulties, and have been enabled to give
a tolerably clear hiftory of the combinations of
oxygen c and nitrogen e.
By employing both analyfis and fynthefis
whenever thefe methods were equally applica-
ble, and comparing expcrin;ents made under
different circumftances, I have endeavoured to
guard again ft fources of error; but I cannot
fla'tter my felf that I have altogether avoided
them. The phyfical fcienccs are alnjoft
wholly dependant on the minute obfervatiori
and comparifon of properties of things not im-
mediately obvious to the fenfes : and from the
rlifficulty of difcovCrrng every poflible mode of
examination, and from the modification of p§r-
( xiu. )
ceptlons by the ilate of feeling, it appears nearly
jmpoffible that all the relations of a feries of
phaenomena/can be difcovered by a fingleinvefti-
gation, particularly when thefe relations are
complicated, and many of the agents unknown.
Fortunately for the aflive and progreffive na-
ture of the human mind, even experimental
refearch is only a method of approximation to
truth.
In the arrangement of fa6ls, I hava been
guided as much as poffible by obvious and
fimple analogies only. Henc€ I have feldom
entered into theoretical difcuffions, particularly
concerning light, heat, and other agents, which
are known only by ifolated efFedls.
Early experience has taught me the folly
of hafty generalifation. We are ignorant of the
laws of corpufcular motion ; and an immenfe
rnafs of minute obfervafions concerning themore
complicated chemical changes mufl be cdl^edied,
probably before we fhall be able to afcertain
even whether we are capable of difcoveringthem.
Chemiftry in its prefent ftate, is fimply a partial
( xiv. 7
hiftory of phasRomena, confifting of many
feries more or lefs extenfive of accurately con-
nc<^ed (siiSis.
With the moft important of thefe feries, the
arrangement of the combinations of oxygene or
the antiphlogiftic tlieory difcovered by Lavoi-
lier, the chemical details in this work are
capable of being conne6\ed.
In the prefent ftate of fcience, it will be
unnccefTary to enter into difcuffions concern-
ing the importance of inyeftigations relating
to the properties of phyfiological agents, and
the changes effedled in them during their ope-
ration. By means of fuch inveftigations, vvc
arrive nearer towards that point frojn which we
fhall be able to view what is within the reach
of difcovery, and what mud for ever remain
unknown to us, in the phaenomena of organic
life. They are of immediate utility, by enabling
us to extend our analogies fo as to inveftigate
the properties o( untried fubftances, with greater
acciiracy and probability of fuccefs.
( XV. )
The firft Refearch in this work chiefly relates
to the produdlion of nitrous oxide and the ana-
lyfis of nitrons gas and nitrous acid. In this
there is little that can be properly called mine j
and if by repeating the experiments of other
chemiftsj I have fometimes been able to make
more minute obfervations concerning phaend-
mena, and to draw different conclulions, it is
wholly owing to the life I have made of the
inftruments of invefligation difcovered by the
illuftrious fathers of chemieal philofophy,* and
fo fuccefsfully applied by them to the difcovery
of truth.
In the fecond Refearch the combinations and
compofition of nitrous oxide are inveftigated,
and an account given of its decompofition by
moft of the combuftible bodies.
The third Refearch contains obfervations on
the a<3ion of nitrous oxide upon animals, and
* Cavendifli, Prieftley, Black, Lavoifier, Schecle, Kir-
wan, GuytoDj Berthollet,. &c\
( xvi. )
an inveftigation of the changes efFefled in it
by refpiration.
In the fourth Refearch the hiftory of the
refpirability and extraordinary effects of nitrous
oxide is given, with details of experiments
on its powers made by different individuals.
I cannot clofe this introdu6iion, without
acknowledging my obligations to Dr. Beddoes.
In the conception of many of the following
experiments-, I have been aided by his conver-
fation and advice. They were executed in an
Inftitutipn which owes its exiftence to his
benevolent and philofophic exertions.
Voivry-Square, HotiveUsy Brtjiol.
June 25 th, 1800.
RESEARCH I.
CONCERNING THE ANALYSIS
OF
NITRIC ACID AND NITROUS GAS.
AND
THE PRODUCTION OF
NITROUS OXIDE.
^N M..
1^^ JAN 6 ,^77 ^
RESEARCH I. '"'^^^i^l^AR
INTO THE PRODUCTION AND ANALYSIS
OP
NITROUS OXIDE,
AND
THE AERIFORM FLUIDS RELATED TO IT.
DIVISION I.
EXPERIMENTS and OBSERf'ATIONS on the com-
position o/" NITRIC ACID, and on its combinations
with Water and Nitrous Gas.
I. 1 HOUGH fince the commencement
of Pneumatic Chcmiftry, no fubftance has been
more the fiibjed of experiment than Nitrous
Acid ; yet ft ill the greateft uncertainty exifts
with regard to the quantities of the principles
entering into its compofition.
In comparing the experiments of the illus-
trious Cavendifh on the fynthefis of nitrous
acid, with thofe of Lavoifier on the decompo-
pofttion of nitre by charcoal, we find a much
greater difference in the refults than can be
( 2 )
accounted for by iuppofing the acid formed,
and that decompofed, of different degrees of
oxygenation.
In the moft accurate experiment of Cavendifb,
when the nitrous acid appeared to be in a ftate
of deoxygcnation, 1 of nitrogene combined with
about 2,346 of oxygene.* In an earlier experi-
ment, when the acid was probably fully
oxygenated, the nitrogene employed was to
the oxygene nearly as 1 to 2yg2.'jf
Lavoilier, from his experiments on the de-
compofition of nitre, and combination of ni-
trous gas and oxygene, concludes, that the
pcrfedlly oxygenated, or what he calls nitric
acid, is compofed of nearly 1 nitrogene, with
3,9 of oxygene ; and the acid in the laft ftatc
of deoxygenation, or nitrous acid, of about 3
oxygene with 1 nitrogene.;};
* Phil. Tranf. v. 78. p. 270. f Phil. Tranf. v. 75, p. 381.
X Elem. Kerr's Tranf. page 76, and 2l6, and Mem. dci
Sav. Etrang. torn. 7, page 629.
( 3 )
Great as the difference is between the efti-
rnations of thefe philofophers, we find differ-
ences flill greater in the accounts of the quantities
of nitrous gas neceflary to faturate a given quan-
tity of oxygeijc, as laid down by very accurate
experimentalifls. On the one hand^ Prieflley
found 1 of oxygene condenfed by 2 of nitrous
gas, and Lavoifier by 1 |. On the other,
Ingenhouz, Scherer, and De la Metherie,
Hate the quantity tieceflary to be from 3 to 5.^^
Humbolt, who has lately invefligated Eudi-
ometry with great ingenuity, confiders the mean
quantity of nitrous gas neceflary to faturate 1
of oxygene, as about 2,55.-^
II. To reconcile thefe different refults is
impolfiblc, and the immediate connedlion of
the fubjefl with the produdlion of nitrous
oxide, as well as its general importance, obliged
me to fearch for means of accurately deter-
* Ingenhouz fur les Vegetaux, pag. 205. De la Metheri«i
Eflai fur differens Airs, pag. 252.
t Annales de Chimic, tome 28, p, l68.
( 4 )
mining the compofitlon of nitrous acid in its
different degrees of oxygenation.
The firft defideratiim was to afcertain the
nature and compofition of a fluid acid, which
by being deprived of, or combined with nitrous
gas, might become a ftandard of comparifon
for all other acids.
To obtain this acid I fhould have preferred
the immediate combination of oxygene and
nitrogene over water by the eledlric fpark, had
it been pofFible to obtain in this way by a com-
mon apparatus fufficient for extenfive examina-
tion ; but on carefully perufing the laborious
experiments of Cavendifh, I gave up all thoughts
of attempting it.
My firft experiments were made on the
decompofition of nitre, formed from a known
quantity of pale nitrous acid of known fpccific
gravity, by phofphorus, tin, and charcoal : but
in thofe procefTes, unafcertainable quantities of
nitrous acid, with cxcefs of nitrous gas, always
efcaped undecompounded, and from the non-
coincidence of refults, where different quanti-
( 5 )
ties ofcombuftible fubftances were employed,
I had reafons for believing that water was
generally decompofed.
Before thefe experiments were attempted, I had
analized nitrous gas and nitrous oxide^ in a man-
ner to be particularly defcribed hereafter ; fo
that a knowledge of the quantities of nitrous
gas and oxygene entering into the compofition
of any acid, enabled me to determine the pro-
portions of nitrogene and oxygene it contained.
In confequence of which I attempted to com-
bine together oxygene and nitrous gas, in fuch
a manner as to abforb the nitrous acid formed
by water, in an apparatus by which the quanti-
ties of the gafes employed, and the increafe of
weight of the water, might be afcertained ; but
this procefs likewife failed. It was impoffible
to procure the gafes perfectly free from nitro-
gene, and during their combination, this nitro-
gene made to pafs into a pneumatic apparatus
communicating with a vcflel containing the
)vater carried over with it, much nitrous acid
vapor, of different compofition from the acid
abforbed.
( 6 )
After many unfucccfsful trials. Dr. Prieft ley's
experiments on nitrous vapor * induced me
to fuppofe that oxygene and nitrous gas, made
to combine out of the contad of bodies having
affinity for oxygtne, would remain perma-
nently aeriform, and on throwing them fepa-
rately into an exhaufted glafs balloon, I found
that this was a(^ually the cafe ; increafe of tem-
perature was produced, and orange colored
nitrous acid cas formed, which after re-
maining for many days in the globe, at a tem-
perature below 56", did not in the flightcft
degree condenfe.
This fa6l afforded me the means not only of
forming a ftandard acid, but likcwife of afcer-
taining the fpecific gravity of nitrous acid in
its aeriform ftate.
III. Previous to the experiment, for the pur-
pofe of corre61ing incidental errors, I was in-
duced to afcertain the fpecific gravity of the
* Experiments and Obfervations, Vol. iii. lad edition^
page 105, &c.
( 9 )
into an exhaufted balloon, increafed it in weight
25,5 grains ; thermometer being 56^ and
barometer 30,9. And allowing for the fmall
quantity of nitrogene in the gas, 100 cubic
inches of it will weigh 34.3 grains.
One hundred and thirty cubic inches of
oxygene were procured from oxide of raangan-
efe and fulphuric acid, by heat, and received in
another mercurial airholder.
10 meafures of it, mingled with 26 of the
nitrous gas, gave, after the refiduum was ex-
pofed to folution of fulphate of iron, rather
more than one meafure. Hence we may con-
clude that it contained about 0,1 nitrogene.
6o cubic inches of it weighed 20,75 grains ;
and accounting for the nitrogene contained in
thefe, 100 grains of pure oxygene will weigh
35,09 grains.
Atmofpherical air was decern pofed by nitrous
gas in excefs; and the refiduum waflied with
folution of fulphate of iron till the Nitrogene
remained pure ; 8/ cubic inches of it weighed
26,5 grains, thermometer being 48% barometer
30,1 ; 100 will confequently weigh 30,45.
( 10 )
Qd cubic inches of the air of the laboratory
hot deprived of its carbonic acid, weighed
28,75 grains ; thermometer 53, barometer 30 ;
100 cubic inches will confequently weigh 3 1,9.*
16 meafures of this air, with ]6 nitrous gas,
of known compofition, diminifhed to 19.
Hence it contained about ,26 oxygene.^
In comparing my refults with thofe of Lavoifief
and Kirwan, the eftimation of the weights of ni-
trogene and oxygene is very little different, the
corrections for temperature and prefTure being
fiiade, from that of thofe celebrated philofophers.
The firfl makes oxygene to weigh -f- 34,21, and
nitrogene 30,o64 per cent ; and the laft, oxy-
gene 34, :}: and nitrogene 30,5.
* A tab4e of the fpecific gravities of theie gafes, and
other gafes, hereafter to be mentioned, reduced to a
barometrical and thermometrical ftandard, will be given
in the appendix.
I 40 meafures, expofed to folution of potafh, gave an
abforption of not quite a quarter of a meafure : hence it
contained an inconfiderable quantity of carbonic acid.
f Traite Elementaire.
+ Effai fur le phlogiftique, page 30.
( 7 )
gafes employed, particularly as I was unac-
quainted with any procefs by which the
weight of nitrous gas had been accurately
determined. Mr. Kirwan's eftimation, which
is generally adopted, being founded upon the
comparifon of the lofs of weight of a Iblutioii
of copper in dilute .nitrous acid, with the quan-
tity of gas produced.*
The inftruments that I made ufe of for con-
taining and meafuring my gafes, were two mer-
curial airholders graduated to the cubic inch of
Everard, and furnifhed with flop cocks.^
* When copper is diflblved in dilute nitrous acid, certain
quantities of nitrogene are generally produced, likewife the
nitrous gas carries off in folution fome nitrous acid.
f This airholdcr, cohlidered as a pneumatic i'nftrumcnt,
is of greater importance, and capable of a more extenfivc
application than any other. It was invented by Mr. W.
Clatfibld, and in its form is analogous to Mr. Watt's
hydraulic bellows, confifting of a glafs bell playing under
the prelTure of the atmofphere, in a fpace between two cy-
linders filled with mercury. A particular account of it will^
b6 given in the appendix.
( 8 )
They were weighed in a glafs globe, of the
capacity of 1Q8 cubic inches, which with the
fmall glafs ftop-cock affixed to it, was equal,
when filled with a^mofpheric air, to 1755
grains. The balance that I employed, when
loaded with a pound, turned with lefs than one
eighth of a gi;ain.
Into a mercurial airholder, of the capacity
of 200 cubic inches, l6o cubic inches of ni-
trous gas w^ere thrown from a folution of mer-
cury in nitrous acid.
70 meafures of this were agitated for fome
minutes in a folution of fulphate of iron,* till
the diminution was complete. The nitrogene
remaining hardly filled a meafure ; and if we
fuppofe with Humbolt -j- that a very fmall por-
tion of it was abforbed with the nitrous gas, the
whole quantity it contained may be eftimated
at 0,0142, or^^.
75 cubic inches received from the airholder
* This abforption will be hereafter particularly treated of.
t Annales dc Chimic. Tome xviii. page 139.
( 11 )
The fpecific gravity of nitrous gas, according
to Kirwan^ is to that of common air as 1 194 to
1000. Hence itfhould weigh about 37 grains per
cent. This difference from my eflimation is not
nearly fo great as I expedted to have found it.§
IV # xhe thermometer in the laboratory
ftanding at 55°, and the barometer at 30, 1, 1 now
proceeded to my experiment. The oxygene that
I employed was of the fame compofition as that
which I had previoufly weighed. The nitrous
gas contained ,0166 nitrogene.
For the purpofe of combining the gafes, a
glafs balloon was procured, of the capacity of
148 cubic inches, with a glafs (lop-cock
adapted to it, having its upper orifice tubulated
and graduated for the purpofe of containing
and meafuring a fluid. The whole weight of
this globe and its appendages, when filled with
common air, was 2066,5 grains.
§ The diminution of the fpeci^c gravity of the gas from
the quantity of nitrogene evolved in his experiment, proba-
bly deftroyed, in fome meafure, the fource of error frora
the nitrous acid carried oven.
* Experiment I.
( 12 )
It was partially exhaufted by the air-pump,
and loft in weight juft 32 grains. From whence
we may conclude that about 15 grains of air
remained in it.
In this ftate of exhauftion it was immediately
cemented to the ftop-cock of the mercurial
airholder, and the communication being made
with great caution, 82 cubic inches of nitrous
gas rufhed into the globe, on the outfide of
which a flight increale of temperature was per-
ceived, while the gafes on the infide appeared
of a deep orange.
Before the common temperature was reftored,
the communication was flopped, and the globe
removed. The increafe of weight was 20,25
grains; whence it appeared that 1,14 grains of
common air, part of which had been contained
in theftop-cocks, had entered with the nitrous gas.
Whilfl it vvas cooling, from the accidental
loofening of the flopper of the cock, 3 grains
more of common air entered.*
* That no greater contradion took place depended on
the folution of the nitrous acid formed in the nitrous gas ;
a phaenonoenon to be explained hereafter.
( 13 )
The communication was now made between
the globe and the mercurial airholder con-
taining oxygene. 64 cubic inches were flowly
prefled in, when the outfide of the globe
became warmer, and the color on the infide
changed to a very dark orange. As it
cooled, 6 cubic inches more flowly entered ;
but no new increafe of temperature, or change
of color took place.
The globe being now completely cold, was
{lopped, removed, and weighed ; it had gained
24,5 grains, from whence it appears that 0,4
grains of common air contained in the ftop-
cocks, had entered with the oxygene.*
To abforb the nitrous acid gas, 4 1 grains of
water were introduced by the tube of the flop-
cock, which though clofed as rapidly as pofTi-
ble, muft have fufFered nearly ,5 grains of air to
* I judged it expedient always to afcertain the quantity
of air in the ftop-cocks by weight, as it was impoffible to
join them fo as to have always an equal capacity. The
upper tubes of the two ftop-cocks not joined, contained
nearly an inch and half.
( 14 )
enter at the fame time, as the increafe of weight
was 4], 5 grains. The dark orange of
the globe diminifhed rapidly ; it became warm
at the bottom, and moifl on the fides. After a
few minutes the color had almoft wholly difap-
peared.
To afcertain the quantity of aeriform fluid
abforbed, the globe was again attached to the
mercurial air apparatus, containing 140 cubic
inches of common air. When the communi-
cation was made, 51 cubic inches rufhed in,
and it gained in weight l6,5 grains.
A quantity of fluid equal to 54 grains was
now taken out of the globe. On examination
it proved to be flightly tinged with green, and
occupied a fpace equal to that filled by 41,5
grains of water. Its fpecific gravity was con-
fequently 1,301.
To afcertain if any unabforbed aeriform ni-
trous acid remained in the globe, 13 grains of
folution of ammonia were introduced in the
fame manner as the water, and after fome mi-
nutes, when the white vapor had condenfed,
( 15 )
(he communication was again made with the
mercurial airholder containing common air.
A minute quantity entered, which could not
be eftimated at more than three fourths of an
inch, and the globe was increafed in weight
about 33,25 grains.*
Common air was now thrown into the globe
till the refidual gafes of the experiment were
judged to be difplaced ; it weighed 2106,5
grains, that is, 40 grains more than it had
weighed when filled with common air before
the experiment.'f'
* That is, by the folution of ammonia, and air,
•f Tlie following is an account of the increafe and dimi-
nution of v/eight of the globe, as it was noted in the jour-
nal.
Globe filled with common air - gr. 2066,5
After exhanftion _ _ . 2034.5
After introdu6tion of nitrous gas, 82
cubic inches - - 2G64,25
After the accidental admiffion of com-
mon air - - - 20^7,25
After the admiffion of oxy gene * 2091,75
— 41 grains of water 2133,25
— • • 51 cubic inches of air 2149,7*5
Taken out 54 grains of folution - 2095,75
Introduced 13 grains of ammoniacal
folution - - - 2109,2*
After introdudlion of common air - 2106,5
( 16 )
And if from thofe 40 grains we take 13 for
the folution of ammonia introduced, the re-
mainder, 27, will be the quantity of folution
of nitrous acid in water remaining in the globe,
which added to 54, equals 81 grains, the whole
quantity formed ; but if from this be taken 41
grains, the quantity of water, the remainder
40 grains, will be the quantity of nitrous acid
gas abforbed in the folution.
To find the abfolute quantity of nitrous acid
formed, we muft find the fpecific gravity of
that abforbed ; but as during, and after its
abforption, 17 grains of air, equal to 53,2 cubic
inches entered, it evidently filled .fuch a
fpace. 53,2 cubic inches of it confe-
quently weigh 40 grains, and 100 cubic
inches 75,17 grains. Then ^']b cubic inches
weigh ,56 grains, and this added to 40, makes
40,56 grains, equal to 57,0 cubic inches, the
whole quantity of aeriform nitrous acid pro-
duced. ^
But the quantity of nitrous gas entering into
this, allowing for the nitrogene it contained, is
( 17 ) •
27,6 grains, equal to about 80,5 cubic inches ^
and the oxygepe is 40,56 — 27,6 = to 12,96
grains, or 36,9 cubic inches.
V. There could ex.ift in this experiment
no circumftance conne61ed with inaccu-
racy, except the impoffibility of very mi-
nutely determining the quantities of com-
mon air which entered with the gafes from
the (top-cocks. But if errors have arifen from
this fource, they mud be very inconfiderable ;
as will appear from a calculation of the fpecific
gravity of the nitrous acid gas, founded on
the volume of the gafes that entered the
globe.
The air that remained in the globa
after exhauftion was 15 grains = 47* cub. in.
The nitrous gas introduced was 82
Common air • - - 13
Oxygene - - - - 70
Common air - - - 1
* Decimals are omitted, becaufe the excefs of the two
firft numbers is exadly corrected by the deficiency of the
iaft.
B
( 18 )
Whole quantity of air thrown into
the globe 2\3
From which fubtradl its capacity 148
The remainder is 65
And this remainder taken from 80^5 nitrous
gas -|- 36,9 oxygene, leaves 52,4 cubic inches,
which is the fpace occupied by the nitrous acid ^
gas^ and which differs from 53,95 only by 1,55
cubic inches.
I ought to have obferved, that before this
conclufive experiment, two fimilar ones had
been made. In comparing the refultsofone
of them, performed with the afli fiance of my
friend, Mr. Joseph Priestley, Dr. Priest-
ley's eldefl fon, and chiefly detailed by him
in the journal, I find a coincidence greater than
could be even well expected, where the pro-
cefles are {o complex. According to that
experiment, 41,5 grains of nitrous acid gas
fill a fpace equal to 53 cubic inches, and
are compofed of nearly 29 nitrous gas, and
12,5 oxygene.
( 19 )
We may then conclude, Firft, tliat 100
cubic inches of nitrous acid^ fuch as exifts in
the ^^ aeriform ftate faturated with oxygene, at
temperature 55% and atmofpheric preffure 30,1
weigh 75,17 grains.
Secondly, that 100 grains of it are compofed
of 68,06 nitrous gas, and 31,94 oxygene. Or
alTuming what will be hereafter proved, that
100 parts of nitrous gas confift of 55,95 oxy-
gene, and 44,05 nitrogene, of 29,9 nitrogene,
and 70,1 oxygene; or taking away decimals,
of 30 of the one to 70 of the other.
Thirdly, that 100 grains of pale green
folution of nitrous acid in water, of fpecific
gravity 1,301, is compofed of 50,62 water,
and 49,38 acid of the above compofition.
VI. Having thus afcertained the compofition
of a flandard acid, my next objedl was to ob-
tain it in a more condenfed ftate, as it was
otherwife impoffible to faturate it to its full
* As is evident from the Jfuperabundant quantity of
©xygene thrown into the giobe.
.^il
( 20 )
extent with nitrous c-as. But this I could efFe6l
in no other way than by comparing mixtures
of known quantities of water^ and acids of dif-
ferent rpecific gravities and colors, with the
acid of 1,301.
For the purpofe of combining my acids with
water, I made ufe of a cylinder about 8 inches
long, and ,3 inches in diameter, accurately
graduated to grain meafures^ and furniflied with
a very tight ftopper.
The concentrated acid was firft flowly poured
into it, and the water gradually added till the
required fpecific gravity was produced ;* the
cylinder being clofed and agitated after each
addition, To as to produce combination without
any liberation of elaftic fluid.
After making a number of experiments with
* The weight of the acid poured into the cylinder being
known, its fpecific gravity was known from the fpace it
occupied in the phial. The weight of water being likewifc
known, the fpecific gravity of the folution, when the com-
mon temperature was produced^ was given by the con-
denfation.
\
( 21 )
acids of different colors in this advantageous
way, I at length found that QO grains of a deep
yellow acid, of fpecific gravity 1,5, became,
when mingled at 40" with 77>5 grains of water,
of fpecific gravity 1,302, and of a light green
tinge, as nearly as poffible refembling that of
the ftandard acid.
Suppofing, then, that thefe acids contain
nearly the fame relative proportions of oxygene
and nitrogene, 100 grains of the deep yellow
acid of 1,5, are compofed of 91,9 grains true
nitrous acid,-{^ and 8,1 grains of water.
To ^fcertain the difference between the com-
poiition of this acid, and that of the pale, or nitric
acid, of the fame fpecific gravity, I inferted 150
grains of it into a fmail cylindrical mattrafs of the
capacity of ,5 cubic inches, accurately graduated
to grain meafures, and connc61cd by a curved
-{- That is, fach as it exlfts in tlie aeriform ftate at 55o.
Ffoiii the ftrong affinity of nitrous acid for water, we may
fuppofe that this acid gas contains a larger proportion of it
than the other eafes.
( 22 )
tube with the water apparatus. After heat had
been applied to the bottom of the niattrafs tbr
a few minutes, the color of the fluid gradually
changed to a deep red, whilft the globules of gas
formed at the bottom of the acid, were al molt
wholly abforbed in palling through it. In a
fhort time deep red vapour began to fill the
tube, and being condenfed by the water in the
apparatus, was converted into a bright green
fluid, at the fame time that minute globules of
gas were given out. As the heat applied be-
came more intenfe, a very Angular phaenomenon
prefented itfelf ; the condenfed vapor, increafed
in quantity, at length filled the curvature of the
tube, and when expelled, formed itfelf into
dark green fpherules, which funk to the bottom
of the water, refted for a moment, and then
refolved themfelvcs into nitrous gas.*
When the acid was become completely pale,
it was fufFered to cool, and weighed. It had
loft near 15 grains, and was of fpecific gravity
* This appearance will be explained hereafter.
( 23 )
1,491. 2 cubic inches and quarter of nitrous
gas only were colleded.
From this experiment evidently no conclu-
fions could be drawn, as the nitrous gas had
carried over with it much nitrous acid (in the
form of what Dr. Prieflley calls nitrous vapor)
and was partially diflblved with it in the water.-l^
To afcertain, then, the difference between
the pale and yellow acids, I was obliged to
make ufe of fynthefis, compared with analylis,
carried on in a different mode, by means of the
following apparatus,
VII. To the flop-cock of the upper cylinder of
the mercurial airholder, a capillary tube was
adapted, bent fo as to be capable of introdudlion
into an orifice in the ftopper of a graduated phial
fimilar to that employed for mingling acids
with water, and fufficiently long to reach the
bottom. With another orifice in the ftopper
of the^ phial was connected a (imilar tube cur-
t This phasncnaenoD will be particularly explained
hereafter.
( 24 )
ved, for the purpofe of containing a fluid, and
of increafed diameter at the extremity.*
50 cubic inches of pure nitrous gas ^ were
thrown into the mercurial apparatus. The
graduated phial^ containing 00 grains of
nitric acid, of fpecific gravity 1,5, was
placed on the top of the airholding cylinder,
and made to communicate with it by means of
the ftop-cock and firit tube. Into the fecond
tube a fmall quantity of folution of potafh was
placed. When all the junctures were carefully
cemented, by prefling on the air-holder, the ni-
trous gas was llowly pafTed into the phial, and
abforbed by the nitrous acid it contained; whilft
the fmall quantities of nitrogene evolved, flowly
drove forward the folution in the curved tube ;
from the height of which, as compared with that
of the mercury in the condudiing tube, the
preflure on the air in the cylinder was known.
•* The outline only of this npparatus is given here, as far
as \va^ neceffary to make the experixnent intelligible ; a
detailed account of it, and of its general application, will
be given in the appendix.
^ fThat is, from nitrous acid and mercury.
( 25 )
In proportion as the nitrous gas was ablbrbcd,
the phial became warm, and the acid changed
color; it firft became ftravv-colored, then
pale yellow, and when about 7^ cubic inches
had been combined with it, bright yellow. It
had gained in weight nearly 3 grains, and was
become of fpecific gravity 1,496.
This experiment afforded me an approxima-
tion to the real difference between nitric and
yellow nitrous acid ; and learning from it that
nitric acid was diminifhed in fpecific gravity
by combination with nitrous gas, I procured a
pale acid of fpecific gravity 1,504.*' After this
acid had been combined in the fame manner
as before, with about 8 cubic inches of nitrous
gas,§ it became nearly of fpecific gravity 1,5,
and had gained in weight about 3 grains.
* A pale acid of 1.52, by being converted into yellow
acid, became nearly of fpecific gravity 15,1.
§ It is impoflible to afcertain the quantity of gas abforbcd
to more than a quarter of a cubic inch, as the firfi: portions
of nitrous gas thrown into the graduated cylinder are com-
bined with the oxygene of the common air in it, to forui
uitrous acid^ and hence the flight excefs of weight.
( 20 )
AfTuming the accuracy of this Qxperiment as
a foundation tor calculation, I endeavoured in
the fame manner to afcertaio the difFej-fences in
the compofition of the orange-colored acids,
and the acids containing (lill larger proportions
of nitrous gas.
93 grains of the bright yellow acid of 1,5
became, when 6 cubic inches of gas had been
pafTed through it, orange colored and fuming,
whilft the undifiblved gas increafed in quantity
fo much as to render it impoflible to confine it
by the folution of potafh. When 9 cubic
inches had pafTed through, it became dark
orange. It had gained in weight 2,75 grains,
and was become of fpecific gravity 1,48 nearly.
Hence it was evident that much nitrous gas had
pafTed through it undiflblved. 25 cubic inches
more of nitrous gas were nowflowly fcnt through
it: it firft became of a light olive, then of a
dark olive, then of a muddy green, then of a
bright green, and laflly of a blue green. After
its afT-unption of this color, the gas appeared to
pafs through it unaltered, and large globules
( 27 )
of fluid, of a darker green than the reft,
remained at the bottom of the cylinder, and
when agitated, did not combine with it. The
increafe of weight was only l grain, and the
acid was of fpecific gravity J, 474 nearly.
In this experiment it was evident that the
unabforbed nitrous gas had carried over with it
a confiderable quantity of nitrous acid. I en-
deavoured to corre6l the errors refulting from
this circumftance, by conne6i:ing the curved
tube firfl with a fmall water apparatus, and
afterwards with a mercurial apparatus ; but
when the water apparatus was ufed, the greater
part of the unabforbed gas was diflblved with
the nitrous acid it held in folution, by the water;
and when mercury was employed, the nitrous
acid that came over was decompofed, and the
quantity of nitrous gas evolved, in confcquence
increafed.
As it was pofiible that a fmall deficiency of
weight might arife from the red vapor given
out during the procelies of weighing and
examining the acid in the lad experiment,
( 2S )
35 cubic inches of nitrous gas were very
flowly pafled through 90 grains of pale nitrous
acidj of rpecific gravity 1,5 : it became of fimi-
lar appearance tothat juft defcribed, had gained
in weight 6,75 grains_, and was become of fpe-
cific gravity 1,475.
Thefe experiments did not afford approxima-
tions fufiiciently accurate towards the compod-
tion of deoxygenated acids, containing more
nitrous gas than the dark orange colored. To
obtain them, a folution confifiing of 94,25
grains of blue green, or perfectly nitrated acid,
(if we may be allowed to employ the term), of
fpceific gravity 3,475, was inferred into a
graduated phial, and connedled by a curved
tube, with the mercurial airholder ; in the
condudor of which a fmall quantity of
water was infcrtcd to abforb the nitrous acid
which might be carried over by the gas. Heat
v.'as flowly a{)plicd to the phial, and nitrous
gas given out with great rapidity. When 4
cubic inches were colledlcd, the acid became
dark olive, v/ hen g dark red, when 13 bright
( ^9 )
orange, and when 18 pale. It had lott 31
grains, and when completely cool, was of foeci-
fic gravity 1,502 nearly. The water in the
apparatus was tinged of a light blue ; from
whence we may conclude that Ibme of the
nitrous gas was abforbed by it with the nitrous
acid : but it will be hereafter proved that the
orange colored acid is the moii nitrated
acid capable of combining undecompounded
with water, and that the color it commu-
nicates to a large quantity of water, is light
blue. If then we take 6,1 grains, the quantity
of gas collci^ed, from 31 the lofs, the remainder
is 24,9, which reafoningfrom the fynthctical ex-
periment, may be fuppofed to contain nearly
3 cubic inches of nitrous gas. Confeque.ntly,
94,25 grains of dark green acid, of fpecific
gravity 1,475, are compofed of nearly 21 cubic
inches, or 7,2 grains of nitrous gas, and 87,05
grains of pale nitrous acid, of 1,504.
VIII. Comparing the different fynthctical and
analytical experiments, we may conclude with
tolerable accuracy, that 92,75 grains of bright
( 30 )
yellow, or fiandard acid of 1,5, are compofed
0(2,75 grains of nitrous gas, and 90 grains of
nitric acid of 1,504; but 92,75 grains of ftandard
acid contain 85,23 grains of nitrous acld^ com-
pofed of about 27,23 of oxygene^ and 58,
nitrous gas : now from 58, take 2,75, and the
remainder 55,25, is the quantity of nitrous gas
contained in QO grains of nitric acid of
1,504 ; confequently, 100 grains of it are
compofed of 8,45 water, and 91,55 true acid,
containing 61,32 nitrous gas, and 30,23 oxy-
gene ; or 27,01 nitrogene, and 64,54 oxygene :
and the nitrogene in nitric acid, is to the oxy-
gene as 1 to 2,389.
IX. My ingenious friend, Mr. James
Thomson, has communicated to me fome
obfervations relating to the compofition of
nitrous acid (that is, the orange- colored acid),
from which he draws a conclulion which is, in
my opinion, countenanced by all the fafls we
are in pofleffion of, namely, " that it ought
" not to be confidcred as a diftindl and lefs
( 31 )
^' oxygenated flate of acid, but fimply as nitric
"^ or pale acid, holding in folution, that is,
'' loofely combined with, nitrous gas."*
It is impoffibleto call any fubftance a fimpleacid
that is incapable of entering undecompounded
into combination with the alkalies, &c ; but it
will appear hereafter that the falts called in the
•* In a letter to me, dated 061. 28, 1799, after giving an
account of fome experiments on the phlogiftication of
nitric acid by heat and light, he fays, " It was from an
" attentive examination of the manner in which the nitric
" acid was phlogifticated in thefe experiments, that I was
'' confirmed in the fufpicion T had long before entertained,
'^ of the real difference between the nitrous and nitric acids,
" It is not enough to ihew that in the nitrous acid, (that is,
" the nitric holding nitrous gas in folution), the proportion
" of oxygene in the whole compound is lefs than that enter-
'^ing into the compofition of the nitric acid, and that it is
" therefore lefs oxygenated. By the fame mode of reafoning
'' we might prove that water, by abforbing carbonic acid
" gas, became lefs oxygenated, which is abfurd. Should
'' any one attempt to prove (which will be nccelfary to fub-
" f^antiate the generally received dodrlne) that the oxygene
" of the nitrous gas combines with the oxygene of the acid,
*' and thenitrogene, in like manner, fo that the reful ting acid,
'* when nitrous gas is abforbed by nitric acid, is a binary
*' combination of oxygene and nitrogene, he would find it
*' fomewhat more difficult than he at firfl imagined ;. it ap-
*' pears to me impo0ible. it is mucli more confonant with
( 32 )
iiew nomenclature nitrites^ cannot be direflly
formed. If^ indeed, it could be proved,
that the heat produced by the combina-
tion of nitrous acid with falifiable bafcs, was
the only caufe of the partial decompofition of
it, and that when this procefs was efFedled in
Aich away as to prevent increafe of temperature,
no nitrous gas was liberated, the common
" experiment to fuppofe that nitrous acid is nothing more
*' than nitric acid holding nitrous gas in folution, which
" might in conformity to the principles of the French
^'nomenclature, becalled nitrate of nitrogene. The difficulty,
" and in fome cafes the impoflibility, of forming nitrites,
" arifes from the weak affinity which nitrous gas has for
f* nitric acid, compared with that of other fubftances ; and
'^ the decompofition of nitrous acid) that is, nitrate of
^' nitrogene) by an alkaline or metallic fubftance, is perfectly
'^ analogous to the decompofition of any other nitrate, the
*' nitrous gas being difplaced by the fuperior affinity of the
*' alkali for the acid.
" Agreeable to this theory, the falts denominated
♦■' nitrites are in fadt triple falts, or ternary combinations of
** nitric acid, nitrous gas, and falifiable bafes."
This theory is perfe6tly new to me. Other Chemifts
to whom I have mentioned it, have likewife confidered it
as new. Yet in a fubfequent letter Mr. Thomfon mentions
that he had been told of the belief of a fimilar opinion
among the French Qhpmilis.
( 33 )
theory might have fomc foundation ; but though
dilute phlogiflicated nitrous acid combines
* with alkaline folutions without decompoiition,
yet no excefs of nitrous gas is found in the
folid fait : it is either difengaged in proportion
as the water is evaporated, or it abforbs oxy-
gene from the atmofpbere, and becomes nitric
acid.
In proportion as the nitrous acids con-
tain more nitrous gas, fo in proportion do they
more readily give it out. From the blue
green acid it is liberated flowly at the tempera-
ture of 30°, and from the green likewife on
agitation. The orange- coloured and yellow
acids do not require a heat above 200® to free
them of their nitrous gas ; and all the
* In fome experiments made on the nitrites of potalli.
and of ammoniac, before I was well acquainted with
Ijhe cpmppfition ,of nUric acid, I fovin^ that a li,gh^ <>Hvie-
colored acid of 1,28; was capable of being faturated by
weak folutions of potalh and ammoniac, without lofing
any ixitirotis gas 3 ,bi;it after tl^eeyaporation of the neutrajifcd
folution, at very low temperatures, the falts in all tlji^ir
properties rcfembled nitrates.
( 34 )
colored acids^ when expofed to the atmofphere
abforb oxygene, and become by degrees pale.
If the nitrous vapour, i. e. fuch as Is
difengaged during the denitration of the
colored acids, was capable of combining with
the alkalies, it might be fuppofed a diftindl
acid, and called nitrous acid ; and the acids
of different colors might be confidered fimply
as compounds of this acid with nitric acid ;
but it appears to be nothing more than a folu-
tion of nitric acid in nitrous gas, incapable of
condenfation, undecompounded, and when
decompounded and condenfed, conftituting
the dark green acid, which is immifcible with
water,-^ and uncombinable with the alkalies.;}:
It feems therefore reafonable, till we are in
pofTeflion of new lights on the fubjedl, to con-
fider, with Mr. Thomfon, the deoxygenated or
nitrous acids fimply as folutious of nitrous gas
t As IS evident from the curious appearance of the dark
green fpherules, rcpulfive both to water, and light green
acid.
X That iSj undecompounded.
( 35 )
in nitric acid, and as analogous to the folutions
of nitrous gas in the fulphuric and marine
acids, &;c. and the (lilts called nitrites, ternary
combinations, fimilar to the triple compounds
compofed of fulphuric acid, metallic oxides,
and nitrous gas.*
Suppofing the truth of thefe principles ac-
cording to the logic of the French nomencla-
ture, there is no acid to which the term nitrous
acid ought to be applied ; but as it has been
ufed to fignify the acids holding in folution
nitrous gas, it is perhaps better ftill to apply it
to thofe fubftances, than to invent for them
new names. A nomenclature, accurately ex-
prefling their conftituent parts, would be too
complex, and like all other nomenclatures
founded upon theory, liable to perpetual alter-
ations. Their compofition is known from their
fpecific gravity and their colors ; hence it is
better to denote it by thofe phyfical proper-
ties : thus orange nitrous acid, of fpecific
gravity 1,480, will fignify a folution of nitrous
^ The exiftence of tliefe bodies will be hereafter proved.
( 36 )
gas in nitric acid, in which the nitric acid is td
the nitrous gas, nearly as 87 to 5, and to the
water as 1 1 to I,
X. The eftimation of the compofition of the
ydlow and orange colored nitrous acids given
in the following table, may be confidered as
tolerably accurate, being deduced from the
lynthetical experiments in the fixth fef^ion,
compared with the analytical ones. But as in
the fynthetical experiment, when the acid be-
came green, it was impoffible to afcertain the
quantity of nitrous gas that pafTed through it
unabforbed, and as in the analyfis the quantity
of nitrous gas diflblvedby the water at different
periods of the experiment could not be afcer-
tained, the accounts of the compofition of the
green acids mnft be confidered only as very
imperfeft approximations to truth.
( 3? )
TABLE I.
Containing Approximations to the quantities ofNITRiC
ACID, NITROUS GAS, and HEATER in NITROUS
ACIDS, of different colors and specific gravities.
100 Parts
Sol. Nitric Acid
YellowNitroueiJ:
Bright Yellow-
Dark Orange
Light Olive X
Dark Olive +
Blight Green %
Blue Green*
of
Specific gra.
NitricAcid
Water
1,504
91,55
8,45
1,502
90,5
8,3
lj500
1,4 80
iii
i
88,94
86,84
8,10
7,6
1,479
86,00
7,55
1,478
85,4
7,5
1,470
84,8
7,44
1,473
84,6
7,4
Nitrous gas.
1,2
2,96
5,56
6,4 5
7,1
7,76
8,00
* The blue green acid is not homogeneal in its compofition, it is
compofed of the blue green fpherules and the bright green acid.
The blue green fpherules are of greater fpecific gravity than the dark
green acid, probably becaufe they contain little or no water.
X The compofition of the acids thus marked, is given from cal-
.calaiions.
( 38 )
TABLfe II.
Binary Proportions of OXrGENE and NITROGEN E
in NITRIC and KITROCS ACIDS."
100 Parts.
Oxy-
Nitro-
k^
Nitro-
Oxv-
'5
gene
gene
5
d
c
1
gene
1
gene
■2,3S9
Nitric Acid
70,50
20,50
Bright yell owNitrous
"
70,10
29,90
Z
1
2,344 j
1
Orange coloured
6g,63
30,37
0
0
1
2,292!
Dark Green
6g,os
30,92
0
1
2,230 j
XL I have before mentioned that dilute nitric
acids are incapable of diffolving fo much nitrous
gas in proportion to their quantities of true
acid, as concentrated ones. During their
abforption of it, they go through limilar changes
of color; 330 grains of nitric acid, of fpecific
gravity 1,36, after 50 cubic inches of gas had
been pafTcd through it, became blue green, and
* Nitrous gas contains 44,05 Nitrogene, and 55,05
Oxygcne, as has been faid before.
( 39 )
pffpecific gravity 1^351. It had gained in
weight but 3 grains ; and when the nitrous gas
was driven from it by heat into a water appa-
ratus^ but 7 cubic inches were colledled.*
From the diminution of fpecific gravity of
nitric acid by combination with nitrous gas,
and from the fmaller attradiion of nitric
acid for nitrous gas, in proportion as it is
diluted, it is probable that the nitrated acids^ in
their combinations with water, do not contradl
fo much as ^ nitric acids of the fame fpecific
gravities. The al^nities refulting from the
fmall attrafl ion of nitrous gas for water, and
its greater attraction for nitric acid, muft be
fuch as to leflen the affinity of nitric acid and
water for each other.
Hence it would require an infinite number
of experiments to afcertain the real quantities of
acid, nitrous gas, and water, contained in the
* A great portion of it, of conrfe, diflblved in the water
with the nitrous acid carried over.
t Their changes of volume, correfponding to changes
of temperature, muft probably, are likewife different.
( 40 )
different diluted nitrous acids ; and after thele
quantities were determined^ they would proba-
bly have no important connexion with the
chemical arrangement. As yet, our inftru-
ments of experiment are not fufficiently exadl
to afford us the means of afcertaining the
ratio in which the attradlion of nitric acid*
for water diminifhes in its progrefs towards
faturation.
The eflimations in the following table, of the
real quantities of nitric acid in folutions of dif-
ferent fpecific gravities, were deduced from
experiments made in the manner defcribed in
fedlion VI, except that the phial employed was
longer, narrower, and graduated to half grains.
The temperature, at the time of combination,
was from 40° to 46°.
* Probably in the ratio of the fquare of the quantity of
water united to it.
( 41 )
TABLE III.
Of the Quantities of True NITRIC ACID in solutions
of different SPECIFIC GRAVITIES.
100 Parts Nitric
Acid of fpecfic
True Acid*
Water
gravity
^
1,5040
91.55
8,45 j
1,4475
80,39
19.61
1,4285
.3
71.65
28,35
1,3900
§
0
62,96
37.04
1,3551
56,88
43,12
1,3186
52,03
47.97
1,3042
49.04
50,96
1,2831
46,03
53,97
1,2090
45,27
54,73
* The quantities of Oxygene and Nitrogene in any folur
tion, may be thus found Let A = the true acid,
X the oxygene, and Y the nitrogene,
Then
238 A
23,9
andY =
239
( 42 )
XII. The blue green fpherules mentioned in
fccSlion V. produced by the condenfation of
nitrous vapor, and by the combination of nitric
acid with nitrous gas, may be confidered as
faturated folutions of nitrous gas in nitric acid.
The combinations of nitric acid and nitrous
gas containing a larger proportion of nitrous
gas, are incapable of exifting in the fluid ftate
at common temperatures ; and, as appears
from the firfl; experiment, an increafe of volume
take place during their formation. They confe-
quently ought to be looked upon as folutions
of nitric acid in nitrous gas, identical with the
nitrous vapor of Prieftley.
From the refearches of this great difcoverer,
we learn that nitrous vapor is decompofablc, both
by water and mercury. Hence it is almoft im-
poflible accurately to afcertain its compofition.
In one of his experiments,^ when more than
130 grains of ftrong nitrous acid were expofed
% ExperimenU and Obfervations j lall edition; vol. 1,
jiBge 384.
( 'IS )
for two days to nearly 247 cubic Inches of
nitrous gas, over water : about half of the
acid was diflblved, and depofited with the gas
in the water.^
XIII. In comparing the refults of my fun-
damentar experiment on the compolition of
nitrous acid, with thofe of Cavendifh, the great
coincidence between them gave me very high
fatisfadlion, as affording additional proofs of
accuracy. If the acid formed in the laft expe.
riment of this ilkil^rious philofopher be fuppofed
analogous to the light green acid formed in my
firft experiment, our cftimations will be almofl
identical.
Lavoifier's account of the compolition of the
nitric and nitrous acids, has been generally
adopted. According to his eftimation, thefe
fubflances contain a much larger quantity of
oxygene than I have affigned to them.
§ Nitrous gas, holding in folution nltrou^J acid, is more
readily abforbed by water than when in its pure form,
from being prefented to it in a more condenfed (late in tho
green acid, formed by the contact of water and nitrous
vapor.
( 44 )
The fundamental experiments of this great phi-
lofopher were made at an early period of pneu-
matic chemiftry^* on the decompofition of nitre
by charcoal ; and he confidered the nitrogcne
evolved, and the oxygene of the carbonic acid
produced in this procefs, as the component
parts of the nitric acid contained in the nitre.
I have before mentioned the liberation of
nitrous acid, in the decompofition of nitre by
combuflible bodies ; and I had reafons for fuf-
pedling that this circumftance was not the only
fource of inaccuracy.
That my fufpicions were well founded, will
appear from the following experiments ;
EXPERIMENT a. I introduced into a
ftrong glafs tube, 3 inches long, and nearly ,3
wide, a mixture of 10 grains of pulverifed,
well burnt charcoal, and 6o grains of nitre. It
was fired by means of touch-paper, and the
tube infi:antly plunged under ajar filled with
* Mem. des Savans Etrangers, v. xi. 226. Vide KirwaQ
fur le phlogiftique pag. 110.
( 4S )
dry mercury. A quantity of gas, clouded with
denfe white vapor was colledled. When this
vapor was precipitated^ Co that the furface of
the mercury could be feen^ it appeared white,
as if adled on by nitrous acid. On introducing
a little oxygene into the jar, copious red fumes
appeared.
EXP. h. A fimilar mixture was fired*
under the jar, the lop of the mercury being
covered with a fmall quantity of red cabbage
juice, rendered green by an alkali. This juice,
examined when the vapor was precipitated, was
become red, and on introducing to it a little
carbonate of potafh, a flight eftervefcence took
place.
EXP. c. Five grains of charcoal, and 20
of nitre, were now fired in the fame manner as
before, the mercury being covered with a flratum
of water. After the precipitation of the vapor
* In this experiment, as well as in the laft, fome of the
mixture was thrown into the jar undecompounded.
( 4G )
on the introduction ofoxygene, no red fumes
were perceived.
EXP. d, 30 grains of nitre, 5 of charcoal^
and five of (ilicious earth,* were now mingled
and fired. The gas received under mercury
was compofed of 18 carbonic acid, and nearly
12 nitrogene.-j- A little muriatic acid was
poured on the refiduum in the tube; a flight
efFervefcence took place.
EXP. <?. The top of the mercury in the jar
was now covered v/ith a little diluted muriatic
acid, and a fmall glafs tube filled with a mixture
of 3 grains of charcoal, and 20 nitre. After
the deflagration, the tube itfelf with the refi-
duum it contained, were thrown into the jar.
The carbonic acid was quickly detached from
them by the muriatic acid, and the whole quan-
* To detach the potafli from the carbonic acid.
f This nitrogcne contained a little nitrous gas, as it gave
red fumes when expofed to the air. The free nitrous acid
was decompofed by the mcrcurV; as it was not covered
with water.
( 47 )
tity of gas generated in the procefs, obtained ;
it meafured 15 cubic inches.
4 cubic inches of it expofed to folution of
potafh, diminifhed to 1 7^; 7 of the remainder,
with 8 of oxygene, gave only 12.
EXP. /. 60 grains of nitre, and q of char-
coal were fired, the top of the mercury in the
jar being covered with water. After the defla-
gration, the tube that had contained them was
introduced, and the carbonic acid contained by
the carbonate of potafh, difengaged by muriatic
acid. 30 meafures of the gafes evolved were
expofed to cauftic potafli ; 20 exaflly v/cre
abforbed, the 10 remaining, with ]0 of oxy-
gene, diminifhed to 17.
EXP. g. A mixture of nitre and charcoal
were deflagrated over a little water in the mer-
curial jar : after the precipitation of the vapor,
the water was abforbed by fih rating paper.
This filtrating paper, heated in a folution of
potafli, gave a faint fmell of ammoniac.
EXP. /j. Water impregnated with the
vapor produced in the deflagration, was heated
( 48 )
with quicklime, and prefeiited feparately i(3
three perfons accuftomed to chemical odors*
Two of them inftantly recognifcd the ammo-
niacal fmcll, the other could not afcertain it.
Paper reddened with cabbage juice was quickly
turned green by the vapor.
Thefe experiments are fufficient to fliew that the
decompoiition of nitre by charcoal is a very com-
plex procefs, and that the intenfc degree of heat
produced may efre6l changes in the fubftances
employed, which we are unable to eflimate.
The produ6i:s, inflead of being fimply car-
bonic acid, and nitrogene, are carbonic acid,
nitrogene, nitrous acid, probably ammonia,
and fometimes nitrous gas. The nitrous acid
is difengaged from the bafe by the intenfe heat.
Concerning the formation of the ammonia, it
is ufelcfs to reafon till we have obtained un-
equivocal teftimonics of its exiftence ; it may
be produced either by the decompoiition of
the water contained in the nitre, by the com-
bination of its oxygcne with the charcoal, and
of its nafcent hydrogene with the nitrogene of
( 49 )
the nitric acid ; or from fome unknown deconl-
pofition of the potafh.
As neither Lavoifier nor Berthollet found
nitrous gas produced in the decompofition of
nitre by charcoal, when a water apparatus was
employed ; and as it was hot uniformly evolved
in my experiments, the mod probable fuppo-
fition is, that it arifes from the decompofition
of a portion of the free nitrous acid intenfely
heated, by the mercury.
In none of my experiments was the whole of
the nitre and charcoal decompofed, fome of it
was uniformly thrown with the gafes into the
mercurial apparatus. The nitrogene evolved,
as far as I could afcertain by the common tefts,
was mingled with no inflammable gas.
If we confider experiment /as accurate, with
regard to the relative quantities of carbonic acid
and nitrogene produced, they are to each other
nearly as 20 to 8 ; that is, allowing 2 for the
nitrous gas, and confequently, reafoning in the
fame manner as Lavoifier, concerning the com-
pofition of nitric acid, it fhould be compofed
( 50 )
df I nitrogene to 3,33 oxygerle. But thougli
the quantity of oxygene in this eftimation is
far fhort of that given in his, yet ftill it is too
much. From whatever fource the errors arife,
whether from the evolution of phlogifticated
nitrous acid, or the decompofition of water, or
the produdion of nitrous gas, they all tend to
increafe the proportion of the carbonic acid to
the nitrogene.
I am unacquainted with any experiment from
which accurate opinions concerning the drfFer-
ent relative proportions of oxygene and nitrogene
in the nitric and nitrous acids could be deduced.
Lavoifier's calculation is founded on his fundi-
tnental experiment, and on the combination of
nitrous gas and oxygene.
Dr. Frieftley's experiment mentioned in
fedion 1*2, on the abforption of nitrous gas by
nitrous acid, from which Kirwan* deduces the
XJompofition of the differently colored nitrous
acids, was made over water, by which, as is
* Eflajr 00 phlogiftoi*,-
( 51 >
evident from a minute examinatiati of thefa<3s|j
the greater portion of the nitrous gas employed
was abforbed.
XIV. The opinions heretofore adopted
l*efpe6ling the quantities of real or true acid
in folutions of nitrous acid of different fpecific
gravities, have been founded on experiments
made on the nitro-neutral falts, the moft accu-
f Dr. Prieftley fays, *' Maving filled a phial containing
<f exa6tly the quantity of four pennyweights of water, witir
** ftrong, pale, yellow fpirit of nitre, with its mouth quite
" clofc to the top of a large receiver flandiug in water, 1
^ carefully drew out almoft all the common aii', and then
*' filled it with nitrous air j and as this was abforbed, I kept
** putting in more and more, till in lefs than two days it
" had completely abforbed 130 ounce meafures. Prefently
*' after this procefs began, the furface of the acid affiimed
*' a deep orange color, and when 20 or 30 ounce meafures
" of air were abforbed, it became green at the top : this
" green dcfcended lower and lower, till it reached the
" bottom of the phial. Towards the end of the procefs,
'* the evaporation was perceived to be very great, and when
** I took it out, the quantity was found to have diminifhed
*' to one half. Alfo it had become, by means of this pro-
^* cefs, and the evaporation together, exceeding weak, and
" was rather blue than green."
Exj^eriments and OhfervattonSy vol. 1, p. 364. Laft edition^.
( 62 )
rat^, of which .are thofe of Kirwan, Bergman,
and Wenzel. The great difference in the
refults of thefe celebrated men, proves the
difficulty of the inveftigation, and the exiftence
of fources of error.* Kirwan deduces the
compofition of the folutions of nitrous acid in
water, from an experiment on the formation of
nitrated foda. In this experiment, 36,05 grains
of foda were faturated by 145 grains of nitrous
acid, of fpecific gravity 1,2754. By a tefl
experiment, he found the quantity of fait formed
tp be 85,142 grains.-j^ Hence he concludes
that 100 parts of nitrous acid, of fpecific gravity
1,5543, contain 73,54 of the (Irongeft, or
mofl concentrated acid.
Suppofing his eftimation perfectly true, 100
parts of the aeriform acid of 55° would be com-
pofed of 74,54 of his real acid, and 25,46
water. In examining, however, one of his later
* See Mr. Keir s excellent obfervations on this fubjedt,
Chcm. Dia. Art. Acid.
f Irifti Tranfaaions, vol. 4, p. 34,
( 53 )
experiments,* we fliall frad reafons for conclu-
ding, thai the acid in nitrated foda cannot con^
tain much lefs water than the aeriform acid. A
folution of carbonated foda, containing 125
grains of real alkali^ was faturated by 306,2
grains of nitrous acid, of fpeeific gravity 1,4 16,
The evaporation was carried on in a temperature
not exceeding 120% and the refiduum expofed
to a heat of 400^ for fix hoars, at the end of
which time it weighed 308 grains. Now ac-
cording to my eflimation, 306 grains of nitric
acid, of 1,4]6, fhould contain 215 true acid ;
and we can hai-dly fuppofe, but that during the
^evaporation and confequent long expofure to"
heat, fomeofthe nitrated foda was loft with
the vvater.
Bergman eftimates the quantity of water in
this fait at 25, and the acid at 43 per cent ; but
his real acid was not fo concentrated as Kir-
\Van% confequently the nitric acid in nitra-
ted foda fhould contain more vvater than my
true acid.
* Addit. ObC pag. ;4.
t 54 )
Wenzel, from an experiment on the compor^
fition of nitrated (bda, concludes that it con-
tains 37,48 of alkali, and 62,52 of nitrous acid ;
and 1000 of this acid, from Kirwan's calcula-
tion, contain 812,6 of his real acid; confer
quently, 100 parts of my aeriform acid fhould
contain 93,28 of Wenzers acid, and 6,72 of
water.
I faturated with potafh 54 grains of folutlon
of nitric acid, of fpecific gravity l ,30 1 . Evapo-
rated at about 212°, it produced 66 grains of
nitre. This nitre expofed to a higher tempera-
ture, and kept in fufion for fome time, was
reduced to 60 grains.
Now from the table, 54 of 1,301, (hould
contain 26,5 of true acid. But according to
Kirwan's eftimation, 100 parts of dry nitre
contain 44* of his real acid, with 4 water ;
confcquently 60 fhould contain 26,4.
Again, 90 grains of acid, of fpecific gravity
1,504, faturated with potafh^ and treated ia
* Additional pbfervation«, page 7Q>
( 55 )
the fame manner, gave 173 grains of dry nitre.
Confequently, 100 parts of it fhould contain
47^3 grains of true acid.
Now Lavoifier-J- allows about 51 of dry
acid to 100 grains of nitre, and Wenzel 52.
From Berthollet's:}: experiments, 100 grains
of nitre, in their decompofition by heat, give
out nearly 49 grains of gas. ^
Hence it appears that the aeriform acid, that
is, the true acid of my table, contains rather
lefs water than the acid fuppofed to exift in
nitre^
t Elements, pag. 103, Kerrs Tranflatiou.
X Mem, Acad. 178/,
§ As well as oxygene and nitrogene/ Mr. Watt's experi-
ments prove that much phlogifticated nitrous acid is pro-
duced.
DIVISION II.
EXPERIMENTS and OBSERVATIONS on the com--
position of AMMONIAC and on its combinations with
WATER and NITRIC ACID.
J. Analysis of AMMONIAC or VOLATILE ALKALL
X HE formation and decompofition of volatile
alkali in many procefles, was obferved by Prieft-
ley, Scheele, Bergman, Kirwan, and Higgins ;
but to Berthollet we owe the difcovery of its
conftituent parts, and their proportions to each
other. Thefe proportions this excellent philo-
fopher deduced from an experiment on the
decompofition of aeriform ammoniac by the
eledric fpark :* a procefs in which no apparent
fource of error exifls.
* Jcurnal de Phyfique. \7Q6, Tom, 2, pag. I'^Gt.
( 57 )
Since, hoWever, his eftimations have bee^
made, the proportions of oxygene and hydro-
gene in water have been more accurately de-
termined. This circumftance, as well as the
convi6^Ion of the impollibility of too minutely
fcrutinizing fads, fundamental to a great mafs
of reafoning, induced me to make the follow-
ing experiments.
A porcelain tube was provided, open at both
ends, and well glazdd inMe and outfide, its
diameter being about ,5 inches. To one end
of this, a glafs tube was affixed, curved for the
purpofe of communicating with the water appa-
ratus. With the other end a glafs retort was
accurately connedled, containing a mixture of
perfedly cauftic flacked lime, and muriate of
ammoniac.
The water in the apparatus for receiving the
gafes had been previoufly boiled, to expel the
air it might contain, and during the experiment >b
was yet warm.
When the tube had been reddened in a fur-
nace adapted to the purpofe, the flame of a
( 58 >
Spirit lamp was applied to the bottom of the
retort. A great quantity of gas was collefled
in the water apparatus j of this the firft portions
were rejedled, and the laft transferred to the
mercurial trough.
A fmall quantity examined, did not at all
diminifh with nitrous gas, and burnt with a
lambent white flame, in contaiSl with common
0,^ of this gas, equal to 1 10 grain meafures,
were fired with 2, equal to 80, of oxygene, in
a detonating tube, by the eledlric fpark. They
were reduced to 2^, or go. On introducing
to the remainder a folution of ftrontian, it be-
came flighlly clouded on the top, and an
abforption of Tome grain meafures took place.
It was evident, then, that in this experiment,
charcoal * had been fomehow prefeqt in the
* Though the tube had never been ufcd, and was appa-
rently clean and dry on the iniide, it muft have contained
foraething in the form of duft, capable of furnilhing cUhw
bydro-carbonate, or charcoal.
MV
( 59 )
tube ; which being diflblved by the nafcent
hydrogene, had rendered it flightly carbonated,
and in confequence made the refults incon-
clnlive. ^
A tube of thick green glafs carefully made
clean, was now employed, inclofed in the por-
celain tube. Every other precaution was taken
to prevent the exiftence of fources of error, and
the experiment condu61ed as before.
140 grain meafures of the gas produced,
fired with 120 of oxygene, left, in two experi-
ments, nearly 110. Solution of ilrontian placed
in contadl with the refiduum, did not become
clouded, and no abforption was perceived.
Now ] 5o meafures of gas were deflroyed,
and if we take Lavoifier's and Meufnier's efli-
mation of the compofition of water, and fuppofe
the weight of oxygene to be 35 grains, and that
of hydrogene 2,6 the hundred cubic inches; the
oxygene employed will be to the hydrogene as
243 to 576. Put X for the oxygene, and j' for
the hydrogene.
( 6q )
Then x+y = 160
X ; y :: 243 : 576
243 y
9C =
576
839^= 86400
yz=z 105 Xz=45
And 140 — 105 z=z 35
Confequently, the nitrogene in ammoniac is
to the hydrogene as 35 : 105 in volume : and
13,3 grains of ammoniac are compofed of 10,6
nitrogene, (fuppofing that 100 cubic inches
weigh 30,45 grains) and 2,7 hydrogene.
According to Berthollet, the weight of the
BJtrogene in ammoniac is to that of the hydro-
gene as 121 to 29.^ The difference between
this eftimation and mine is fo fmall as to be
almoft unworthy of notice, and arifes moft pro-
bably from the flight difference between the
accounts of Lavoifier apd Monge, of the com-
pofition of water, and the different weights
afligned to the gafes employed.
* Journal de Phyfique, 1786, t. 2, 177.
( 61 )
We may then conclude, that 100 grains of
ammoniac are compofed of about 80 nitrogene,
and 20 hydrogene.
The decompofition of ammoniac by heat, a5
well as by the ele<?lric fpark, was firfl: difcovered
by Prieftley. In an experiment-l-when aeriform
ammoniac was fent through a heated tube from
a cauftic folution of amnioniac in water, this
great difcoverer obferved that an inflammable
gas was produced, though in no great quan-
tity, and that a fluid blackened by matter, pro-
bably carbonaceous, likewifc canne over.
In my experiments the whole of the ammo-
niac appeared to be decompofed ; the quantity
of gas generated was immenfe, and not clouded,
as is ufually the cafe with gafes generated at
high temperatures. It is poffible, that the larger
quantity of water carried over in his experir
ment, by its flrong attradlon for ammoniac in
the aeriform flate, might have, in fome mea-
fure, retarded the decompofition. It is how-
* Phil. Tranf. vol. T9> page 2g4,
( 62 )
ever^ more probable to fuppofe, that a fiffure
cxifled ill the earthen tube he employed;,
through which a certain quantity of gas efcaped,
and coaly matter entered.
PrJeftley found that the metallic oxides
when ftrongly heated, decompofed ammoniac^
the metal being revivified and water and nitro-
gene produced.* The eftimations of the com-
pofition of ammoniac that may be deduced from
his experiments on the oxide of lead, differ very
little from thofe already detailed.
II. Specific gravity of Ammoiiac.
From the great folubility of ammoniac in
water, it is difficult to afcertain its fpecific
gravity in ihe fame manner as that of a gas
combinable to no great extent with that fluid.
It is impoffible to prevent the exiftence of a
•Vol. 2, page 398.
( 04 )
to communicate with the airholder, the curved
tube containing a fmall quantity of water.
The gas was flowly pafled into the fluid, and
the globules wholly abforbed before they
reached the top ; much increafe of temperature
being confequent. When the abforption was
compleat, the phial was increafed in weight
exadly 9 grains. "
This experiment was repeated three times.
The difference of weight, which was probably
connedf ed with alterations of temperature and
prefTure, never amounted to more than one
fixth of a grain.
We may then conclude, that at temperature
58°, and atmofpheric prefTure 29,6, 100 cubic
inches of ammoniac weigh 18 grains.
According to KirwaU;, 100 cubic inches of
alkaline air =^ weigh 18,1 6 grains; barometer
3Qo, thermometer 61. The difference between
thefe eflimations, the corredions for tempera-
ture and prefTure being made, is trifling.
' * Additional 01»fervations, page 107.
( 6s )
fmall quantity of folution of amnroniac in the
mercurial airholder,-}- or apparatus containing
the gas ; and during the diminution of the
preifure of the atmofpherc on this folution,^ a
certain quantity of gas is hberated from it, and
hence a fource of error.
Xo afccrtain, then, the weight of ammoniac,
I employed an apparatus fimilar to that ufed
for the abforption of nitrous gas by nitric
^cid.
50 cubic inches of gas were collei5led in the
mercurial airholder, from the decompofition of
muriate of ammoniac by lime ; thermometer
being 58°, and barometer 29,6.
100 grains of diluted fulphuric acid wefe
introduced into the fmall graduated cylinder,
which after being carefully weighed, was made
t Ammoniac generated at a temperature above that of
the ^tmofphere, always depolits ammoniacal folution during
its rcdudlon to the common temperature.
X By the introdu6lion of arriform ammoniac into tlie
c;ihaufted globe.
( 65 )
III. Of the quantities of true Ammoniac in
Aqueous Ammoniacal Solutions^ of different fpe-
cific gravities.
To afcertain the quantities of ammoniac, luch
as exifts in the aeriform flate, faturated with
moifture, in foUitions of different fpecific gra-
vities, I employed the apparatus for abforption
fo often mentioned. Thermometer being 52**,
the mercurial airholder was filled with ammo-
niacal gas, and the graduated phial, containing
50 grains of pure water, conned^ed with it.
During the abforption of the gas, the phial
became warm. When about 30 cubic inches
had been paffed through, it was fuffered to
cool, and weighed : it had gained 5,25 grains,
and the fluid filled a fpace equal to that occupied
by 57* grains of water.
* It is neceflary in thefe experiments, that the greateft
care be obfervcd in the introdu6tion and extradion of the
capillary tube. If it is introduced dry, there will be a
fource of error from the moifture adhering to it when
taken out. 1 therefore always wetted it before its intro-
dudtion, and took care tliat no more fluid adhered to it
after the experiment, than before.
{ <56 )
Confequently, 100 grains of folution of am-
moniac in water of fpecific gravity ,9684 con-
tain 9,502 grains of annmoniac.
The apparatus being adjufted as before, 50
grains of pure water were now perfe6tly fatu-
rated with ammoniac. They gained in weight
17 grains, and when perfectly cool, filled a
ipace equal to 74 of water Confequently ]00
grains of aqueous ammonia! folution of fpecific
gravity ,9054 contain 25,37 grains of ammo-
niac.
The two folutions were mingled together ;
but no alteration of temperature took place.
Confequently the refulting fpecific gravity
might have been found by calculation.
On mingling a large quantity of cauftic folu-
tion of ammoniac with ^ of its weight of water, of
cxadly the fame temperature, no alteration of it
was perceptible by a fcnfible thermometer. —
Hence the two experiments* being afTumed as
* Previous to thofe experiments, I had made a number
of others on the combination of ammoniac with water. —
My defign was, to afccrtain the diminution of fpecific
( 67 )
data, the intermediate eftimations in the fol-
lowing table, were found by calculation.
gravity for every three grains of ammoniac abforbed j but
this I found impoffible. The capillary tube, when takeri
out of the phial, always carried with it a ncinute portion
of the folution, which partially evaporated before it could
be again introduced 3 and thus the fources of error increafed
in proportion to the number Of examinations.
( 68 )
TABLE IV.
Of approximations to the quantities of AMMONIAC^
such as exists in the aeriform statcy saturated with
■water at ^20, in AQUEOUS AMMONIAC AL SOLU-
TIONS of different specific gravities.
100
Specific gra.
Ammoniac
Water.
9054
25,37
74,63
9166
22,07
77.93
9255
19,54
80,46
9326
17>52
82,48
9385
5,88 ^
84,12
9435
c
14,53
85,47
9476
C
13,46
86,54
9513
u
12,40
87,60
9545
11,56
88,44
9573
10,82
89,18
9m
10,17
89,83
9619
9,60
90,40
9684
9,50
90,5
9639
9,09
90,91
9713
^ 7,17
92,83
* As yet no mode has been difcovered for obtaining gafes
in a date of abfolute drynefs ; confequently we are igno-
rant of the different quantities of water they hold in folu-
tion at different temperatures. As far as we are acquainted
with the combinations of ammoniac, there is no flate in
which it exifts fo free from moifturc, as when aeriform,
at low temperatures.
.( 60 )
That no confiderable fource of error exiftcd
in the two experiments, is evident from the
trifling difference between the eftimations of
the quantities of real ammoniac, in the folu-
tion o( ,q684, as found in the firft experiment,
and as given by calculation from the laft.
The quantity of ammoniac in a folution of
fpecific gravity not in the table, may be thus
determined — Find the difference between the
two fpecific gravities neareft to it in the table ;
d, and the difference between their quantities
of alkali, i? ; likewife the difference between
the given fpecific gravity and that neareft to it, c,
h c
then d \ 1? \\ c \ x and x =
d
Which, added to the quantity of the lower
fpecific gravity, is the alkali fought.
The differences in fpecific gravity of the
folutions of ammoniac at temperatures between
40° and Qb^ * are fo trifling as to be hardly
* The expanfion from increafe of temperature is proba-
bly great in proportion to the quantity of ammoniac io
the folution.
( 70 )
afcertainable, by our imperfc6l inflruinerits, and
confequently are unworthy of notice.
It is poffible at very low temperatures to ob-
tain ammoniacal folutions oflefs ipecific gravity
than ,9, but they are incapable of being kept for
any length of time under the common preflTure
of the atmofphere.
IV. Combinations of Ammoniac with Kitric
Acid. Compojition of Nitrate of Ammoniac y &c.
200 grains of ammoniacal folution, of fpeci-
fie gravity ^Q05d, were faturated by 385,5
'grains of nitric acid, of fpecific gravity 1,306.
The combination was effected in a long phial,
the nitrous acid added very ilowly, and the
phial clofed after every addition, to prevent any
evaporation in confequence of the great increafe
of tempcrature.-l- The fpecific gravity of the
Jolution, when reduced to the common tem-
perature, was 1,15. Evaporated at a heat of
I From ^he ccmbiaation,
( ?i )
:212^4 it gave 254 grains of fait of fibrous
cryftalization. This fait was diflblved in 331
grains of water ; the fpecific gravity of the
foliition was 1,148 nearly.
Hence it was evident that fomc of the fait
had been loft during the evaporation.
To find the quantity loft, fibrous nitrate of
ammoniac was difiblved in fmall quantities in
the folutioUj the fpecific gravity of which was
examined after every addition of 3 grains.
When Ingrains had been added to it, it became
of 1,15.
Confequently, the folution compofed of 200
grains of ammoniacal, and of 385,5 of nitric
acid folution, contained 262 grains of fait of
fibrous cryftalization, and of this fait 8 grains
were loft during the evaporation.
But the alkali in 200 grains of ammoniacal
folution of ,9056 ==:: 50,5 grains. And the
true nitric acid in 385,5 grains of folution of
1,306 = IQO grains.
t I had before proved that at this temperature the fait
neither decompofed nor fublimed.
( 72 )
Then 262 — 240,5 = 21,5, the quantity of
water.
And 262 grains of fibrous cryftalized nitrate
of ammoniac, contain 19O grains true acid,
50,5 ammoniac, and 21,5 water. And 100
parts contain 72,5 acid, 19,3 ammoniac, and
8,2 water.
In proportion as the temperature employed
for the evaporation of nitro-ammoniacal folu-
tions, is above or below 212°, fo in proportion
does the fait produced contain more or lefs
water than the fibrous nitrate. But whatever
may have been the temperature of evaporation,
the acid and alkali appear always to be in the
fame proportions to each other.
Of the falts containing different quantities of
water, two varieties muft be particularly noticed.
The prifmatic nitrate of ammoniac, produced at
the common femperaturesof the atmofphere, and
containing its full quantity of water of cryftali-
fation ; and the compa6l nitrate of ammoniac,
either amorphous, or compofcd of delicately
needled cryflals, formed at 300°, and containing
( 78 )
but little more water than exifts in nitric acid
and ammoniac.
To difcover the cottipolition of the prifmatic
nitrate of ammoniac, 200 grains of fibrous fait
were diflblved in the fmalleft poffible quantity
of water, and evaporated in a temperature not
exceeding 70°. The greater part of the fait
was compofed of perfectly formed tetrahaedral
prifms, terminated by tetrahsdral pyramids.
It had gained in weight about 8,5 grains.
Confcquently 100 grains of prifmatic nitrate
of ammoniac may be fuppofed to contain 69,5
acid, 18,4 ammoniac, and 12,1 water.
To afcertain the compofition of the compadl
nitrate of ammoniac, I expofed in a deep por-
celain cup, 400 grains of the fibrous fait, in a
temperature below 300°. It quickly became
fluid, and flowly gave out its water without any
ebullition, or liberation of gas. When it was
become perfedly dry, it had loft 33 grains.
I fufpeded, that in this experiment fome of the
fait had been carried off with the water ; to
xletermine this, I introduced into a fmall glafs
( 74 )
retort, 46o grains of fibrous fait ; it was kept
at a heat below 320^, in communication with
a mercurial apparatus, in a regulated air-fur-
nace, till it was perfeclly dry : it had loft
23 grains. No gas, except the common air of
the retort came over, and the fluid coUedlcd
bad but a faint tafte of nitrate of ammoniac.
Though in this experiment I had removed
all the fluid retained in the neck of the
retort, flill a few drops remained in the head,
and on the fides, which I could not obtain. It
was of importance to me to be accurately ac-
quainted with the compofition of the compacSl
fait, and for that reafon I compared thefe ana-
lytical experiments with a fynthetical one.
I faturated 200 grains of folution of ammo-
niac, of ,9056 with acid, afcertained the fpe-
cific gravity of the folution, evaporated it at
212°, and fufed and dried it at about 300^—
260^ It gave 246 grains of fait, and a folu-
tion made of the fame fpecific gravity as that
evaporated, indicated a lofs of 9 grains. Con-
fequently, 255 grains of this Hilt contain 50.5
0
( 75 )
grains alkali, igo grains acid^ and 14^5 grains
water.
We may then conclude, that 100 parts of
compad nitrate of ammoniac contain 74,5 acid,
19,8 alkali, and 5,7 water.
V. Decompofuion of Carbonate of Ammoniac
hy Nitric Acid.
In my firft experiments on the produflion of
nitrate of ammoniac, I endeavoured to afcertain
its compofition by decompounding carbon-
ate of ammoniac by nitric acid ; and in making
for this purpofe, the analyfis of carbonate of
ammoniac, I difcovered that there exiiled many
varieties of this falt^ containing very different
proportions of carbonic acid, alkali^ and water ;
the carbonic acid and water being fuperabnn-
dant in it, in proportion as the temperature of
its formation was low, and the alkali in pro-
portion as it Vv^as high : and not only that a
different fait was formed at every different tem-
perature, but likewife that the difference in
( 76 )
(hem was fo great, that the carbonate of ammo*
niac formed at 300^ contained more than 50
per cent alkali, vvhilft that produced at 6o° con-
tained only 20.*
I found 210 grains of carbonate of ammo-
niac, which from com pari fon with other falts
previoufly analifed, I fufpeiled to contain about
20 or 21 per cent alkali, faturated by 200
grains of nitric acid of 1,504. But though
the carbonate was diflblved in much water,
llill, from the fmell of the carbonic acid gene-
rated, I fufpe6l that a fmall portion of the
nitric acid was diilblved, and carried off by
it. The folution, evaporated at about 200%
and afterwards expofed to a temperature below
300°, gave 232 grains of compa6l fait. But
reafoning from the quantity of acid in 200
grains of nitric acid of 1,504, it ought to have
given 245. Confequently 13 were loft by
* A particular account of the experiments from which
thefe fa6ts were deduced, was printed in September, aod
will appear in the firft volume of the Bejcarchcs.
( n )
evaporation ; and this lofs agrees with that in
the other experiments.
V. Decompojition of Sulphate of Ammoniac hy
Nitre»
As a cheap mode of obtaining nitrate of am-
moniac, Dr. Bed DOES propofed to decompofe
nitre by fulphate of ammoniac, which is a well
known article of commerce. From fynthefis
of fulphate of ammoniac, compared w^ith analy-
iis made in Auguft 1799?* I concluded that
100 grains of prifmatic fait were compofed of
about 18 grains ammoniac, 44 acid, and 38
water ; and fuppoling 100 grains of nitre to
contain 50 acid, 100 grains of fulphate of
ammoniac will require for their decompolition
134 grains of nitre, and form 90;9 grains of
compadl nitrate of ammoniac.
* And which will be publiihed, with an account of its
perfed decompofitioa at a high temperature, in the
Befearches.
( 7S )
To afcertain if the fulphate of potaili and
nitrate of ammoniac could be eafily feparated, I
added to a heated faturated folution of fulphate
of ammoniac, pulverifed nitre, till the decom-
pofition was complete. After this decompoli-
lion, the folution contained a flight excefs of
fulphuric acid, which was combined with lime,
and the whole fet to evaporate at a temperature
below 250°. As foon as the fulphate of potafh
began to cryllalife, the folution was fufFered to
cool, and then poured off from the cryftalifed
fait, which appeared to contain no nitrate of
ammoniac. After a feconJ evaporation and
cryftalifation, almofi: the whole of the fulphate
appeared to be depofited, and the folution of
nitrate of ammoniac was obtained nearly pure :
it was evaporated at 212% and gave fibrous
cryftals.
VI. Non-exiflence of Ammonia cal Nitrites.
I attempted in different modes to combine
nitrous acids with ammoniac, fo as to form the
falts which have been fuppofed to exift, and
( 79 )
called nitrites of ammoniac ; but without fuc-
ccfs.
T firft decGmpofed a folution of carbonate of
ammoniac by dilute olive colored acid ; bat in
this procefs, though no heat was generated,
yet all the nitrous gas appeared to be liberated
with the carbonic acid.=^ I then combined a
fmall quantity of ni-trous gas, with a folution
of nitrate of ammoniac. But after evaporating
Ibis folution at 70° — 80°^ I could not detecb
the exiftence of nitrous gas in the fol id fait;
it was given out during the evaporation and
cryftalifation, and formed into nitrous acid by
the oxygene of the atmofpHere. I likewife
heated nitrate of ammoniac to different degrees,
and partially decompofed it, to afcertain if in
any cafe the acid was phlogifticated by heat :
but in no experiment could I detefl the exifience
* When nitrous gas exifts in neutro-faline folutionsj
they are always colored more orlefs inlenfely, from yellow
to olive, in proportion to the quantity combined with
them.
( 80 )
o( nitrous acid in the heated fait, when it had
been previoufly perfedlly neutralifed.
When nitrate of ammoniac, indeed, with
excefs of nitric acid, is expofed to heat, the
fuperabundant nitric acid becomes phlogifti-
cated, and is then liberated from the fait, which
remains neutral.*
We may therefore conclude that nitrous gas
has little or no affinity for folid nitrate of am-
moniac, and that no fubftance exifts to which
the name nitrite of ammoniac can with propriety
be applied.
VII. Of the four ces of error in Analyfis,
To compare my fynthelis of nitrate of ammo-
niac with analylis, I endeavoured to feparate
the ammoniac and nitric acid from each other,
without decompofition. But in going through
the analytical procefs, I foon difcovered that
• Hence a nitrate of ammoniac with excefs of acid,
when expofed to heat, firft becomes yellow, and then
white.
( 81 )
it was impoffible to make it accurate, without
niany collateral laborious experiments on the
quantities of ammoniac folubic in water at
different temperatures.
At a temperature above 212°, I decompofed^
by cauftic flacked lirhe, 56 grains of compact ni-
trate of ammoniac in a retort communicating
with the mercurial airholder, the moifture ia
which had been previoufly faturated with ammo-
niac. 22 cubic inches of gas were colle6led at
38°, and from the lofs of weight of the retort, it
appeared that 13 grains of folution of ammo-
niac in water, had been depofited by the gas.
Now evidently, this folution muft have con-
tained much more alkali in proportion to its
water than that of 55% otherwife the quantity
of ammoniac in 50 grains of fait would hardly
equal 8 grains.*
* The accounts given by different chemifts of the com-
pofition of nitrate of ammoniac, are extremely difcordant^
they have been chiefly deduced from decompofiti9ns of car-
bonate of ammoniac (the varieties of which have been
( S2 )
VIII. Of the lofs of Solutions of titrate of
Ammoniac during evaporation.
The mod concentrated folution of nitrate of
ammoniac capable of exi fling at 60^, is of fpeci-
fie gravity 1,304, and contains 33 water, and
5"J fibrous fait, per cent. When this folution
is evaporated at temperatures betw^een 60° and
100, the fait is increafed in weight by the
addition of water of cryftalifation, and no por-
tion of it is loft.
During the evaporation of folutions of fpccific
gravity 1,146 and 1,15, at temperatures below
120'', I have never dcteded any lofs of fait.
When the temperature of evaporation is 212^,
the lofs is generally from 3 to 4 grains per
cent ; and when from 230^ to the ftandard of
their ebullition, from 4 to 6 grains.
heretofore unknown) by nitrous acids of unknown degrees
of nitration. Hence they are particularly erroneous with
regard to the alkaline part. Wenzel fuppofes it to be 32
per cent, and Kirwan 24. ' Adilit. Ohferv, pag. 120.
i
( 83 )
In proportion as folutions are more diluted,
their lofs in evaporation at equal temperatures
is greater.
DIVISION III.
Decomposition of NITRATE of AMMONIAC : prepa-
ration of RESPIRABLE NITROUS OXIDE; it&
ANALYSIS,
Of the heat required for the decomposition of
NITRATE of AMMONIAC.
JL HE decompofition of nitrate of ammoniac
has been fuppofed by Cornette'* to take place
at temperatures below 212^, and its fublimation
at 234^
Kirwan, from the non-coincidence in the
accounts of its compofition, has imagined that
it is partially decompofable, even by a heat of
To afcerlain the changes efFedled by increafe
of temperature in this fait, a glafs retort was pro-
vided, tubulated for the purpofe of introducing
• Mem. Par. 1783. See Irifli Tranf. vol. 4,
t Addit. Obf. png. ISiO
( 85 )
the bulb of a thermometer. After it had been
made to communicate with the mercurial air-
holder, and placed in a furnace, the heat of
which could be eafily regulated, the thermo-
meter was introduced, and the retort filled with
the fait, and carefully luted; fo that the ap-
pearances produced by different temperatures
could be accurately obferved, and the produdls
evolved obtained.
i
From a number of experiments made in this
manner on different falts, the following con-
clufions were drawn.
lil. Compadi, or dry nitrate of ammoniac^^
undergoes little or no change at temperatures
below 260^.
2dly. At temperatures between 2/5^ and
300°, it flowly fublimes, without decompofition,
or without becoming fluid.
3dly. 2\t 320^ it becomes fluid, decom-
pofes, and flill flowly fublimes ; it neither
affuming, or continuing in, the fluid ftate, witb-
Qiit decompofition.
( S6 )
4thly. At temperatures between 340^ and
480'', it decompofes rapidly.
5thly. The prifmatic and fibrous nitrates of
ammoniac become fluid at temperatures below
300", and undergo ebullition at temperatures
between 36o^ and 400^, without decompofition.
6thly. They are capable of being heated to
430° without decompofition, or fublimation,
till a certain quantity of their water is evapo-
rated.
7thly. At temperatures above 450° they
undergo decompofition, without previoufly
lofing their water of cryflalifation.
II. Decompofition of Kitrate of Ammoniac ;
produBmi of refprahle Nitrous Oxide ; its pro^
perties.
200 grains of compacl nitrate of ammoniac
were introduced into a glafs retort, and dccom*
pofcd flowly by the heat of a fpirit lamp. The
firft portions of the gas that came over were
rcjedled, and the laft received in jars containing
( B7 )
mercury. No luminous appearance was per-
ceived in the retort during the procefs, and
almoft the whole of the fait was refolved into
fluid and gas. The fluid had a faint acid tafte^
and contained fome undecompounded nitrate.
The gas collected exhibited the following pro-
perties.—
a, A candle burnt in it with a brilliant
flame, and crackling noife. Before its extinc-
tion, the white inner flame became furrounded
with an exterior blue one.
h. Phofphorus introduced into it in a flate
of inflammation, burnt with infinitely greater
vividnefs than before.
c. Sulphur introduced into it when burning
with a feeble blue flame, was inftantly extin-
guiflied ; but when in a fl:ate of adtive inflam-
mation (that is, forming fulphuric acid) it
burnt with a beautiful and vivid rofe-colored
flame.
d. Inflamed charcoal, deprived of hydro-
gene, introduced into it, burnt with much
greater vividnefs than in the atmofphc^re.
( S8 )
e. To fome fine twifted iron wire a fmall
piece of cork was affixed : this was inflamed,
and the whole introduced into ajar of the air.
The iron burned with great vividncfs. and threw,
out bright fparks as in oxygen e.
yi 30 meafures of it expofed to water pre-
vioufly boiled, was rapidly abforbcd ; when the
diminution was complete, rather more than a
meafure remained.
g. Pure water faturated with it, gave it out
again on ebullition, and the gas thus produced
retained all its former properties.
h^ It was abforbed by red cabbage juice ;
but no alteration of color took place.
/. Its tafte was diftindly fweet, and its odor
flight, but agreeable.
j, ' It underwent no diminution when ipin-r
gled with oxygene or nitrous gas.
Such were the obvious properties of thp
Nitrous Oxide, or the gas produced by the
decompofition of nitrate of ammoniac in a tem-
perature not exceeding 440^. Other proper-
( 89 )
ties of It will be hereafter demonftrated, and its
affinities fully inveftigated.
III. Of the gas remaining after the abforption of
Mtrous Oxide hy Water,
In expofing nitrous oxide at different times
to rain or fpring water, and water that had
been lately boiled, I found that the gas re-
maining after the abforption was always leaft
when boiled water was employed, though from
the mode of produ6lion of the nitrous oxide, I
had reafon to believe that its compofition was
generally the fame.
This circumftance induced me to fuppofe
that fome of the refiduum might be gas prd-
vioufly contained in the water, and liberated
from it in confequence of the (Wronger affinity
of that fluid for nitrous oxide. But the greater
part of it, I conjectured to confift of nitrogcne
produced in confequence of a complete decom-
pofition of part of the acid, by the hydrogene.
It was in endeavoring to afcertain the relative
( 90 )
I
purity of nitrous oxide produced at different
periods of the procefs of the decompofition of
nitrate of ammoniac, that I difcovered the true
reafon of the appearance of refidual gas.
I decompofed fome pure nitrate of ammoniac
in a fmall glafs retort ; and after fufFering the
firfl portions to efcapc with the common air, I
caught the remainder in three feparatc vefiels
ftanding in the fame trough, filled with water
that had been long boiled, and which at the
time of the experiment was fo warm that I could
fcarcely bear my hands in it. The different
quantities collefled gave the fame intenfe bril-
liancy to the flame of a taper.
26 meafurcs of each of them were feparately
inferted into 3 graduated cylinders, of nearly
the fame capacity, over the fame boiled water.
As the water cooled, the gas was abforbed by
agitation. When the diminution was com-
plete, the refiduum in each cylinder filled,
as nearly as poflible, the fame, fpace ; about
two thirds of a meafure.
To each of the refiduums I added two mea-
('qi )
iurcs of nitrous gas ; they gave copious red
vapor, and after the condenfation filled a fpace
rather lefs than two meafures.
Hence the refidual gas contained more
oxygcne than common air.
I now introduced 26 meafures of gas from
one of the veflels into a cylinder filled vi'ith
unboiled fpring water of the fame kind.* After
the abforption w^as complete, near two meafures
remained. Thefe added to two meafures of
nitrous air, diminifhed to 1,5 nearly.
Thefe experiments induced me to believe
that the rciidual gas was not produced in the
decompofition of nitrate of ammoniac, but that
it was wholly liberated from the water.
To afcertain this point with precifion, I
diftilled a fmall quantity of the farne kind of
water, which had been near an hour in ebul-
lition, into a graduated cylinder containing
mercury. To this I introduced about one third
* Two meafures of air dii'pelled from this water by
boiling, mingled with 2 of nitrous gas^ diminiflicd to 3,4
nearly.
( 92 )
of its bulk, i.e. 12 meafures of nitrous oxide,
which had been carefully generated in the mer-
curial apparatus. After the abforption, a fmall
globule of gas only remained, which could
hardly have equalled one fourth of a meafure.
On admitting to this globule a minute quantity
of nitrous gas, an evident diminution took place.
Though this experiment proved that in pro-
portion as the water was free from air, the reii-
duum was lefs, and though there was no reafon
to fuppofe that the ebullition and diftillation
had freed the water from the whole of the air
it had held in folution, ftill I confidered a
decifive experiment wanting to determine whe-
ther nitrous oxide was the only gas produced in
the flow decompofition of nitrate of ammoniac,
or whether a minute quantity of oxygene wa^
not likewife evolved.
I received the middle part of the product of
a decompofition of nitrate of ammoniac, under
a cylinder filled with dry mercury, and intro-
duced to it Ibme ftrong folution of ammoniac.
After the white cloud produced by the combi-
( 93 )
nation of the ammoniacal vapor with the nitric
acid fiifpended in the nitrous oxide^ had been
completely precipitated, I introduced a fmall
quantity of nitrous gas. No white vapor was
produced.
Now if any gas combinable with nitrous gas
had exifted in the cylinder^ the qnantiry of
nitrous acid produced, however fmall, would
have been rendered perceptible by the ammo-
tiiacal fumes ; for when a minute globule of
common air was admitted into the cylinder^
white clouds were inftantly perceptible.
It feems therefore reafonable to conclude^ »
1. That the refidual gas of nitrous oxide, is
air previoufly contained in the water, (which
in no cafe can be perfectly freed from it by
ebullition), and liberated by the llronger attrac-
tion of that fluid for nitrous oxide.
2. That nitrate of ammoniac, at temperatures
below 440% is decompounded into pure nitrous
oxide, and fluid.
3. That in afcertainlng the purity of nitrous
oxide from its abforption by water, correflions
ought to be made for the quantity of gas dif-
( S4 )
pelled from the water. This quantify in com-
mon water diililled under mercury being about
- ; in water limply boiled, and ufcd when hot,
about ^ ; and in contmon fpring water, l^*
IV. Specific gravity of Nitrons Oxide,
To underfland accurately the changes taking
place during the decompofition of nitrate of
ammoniac, we muft be acquainted with the
fpecific gravity and compofition of nitrous
oxide.
90 cubic inches of it, containing about —
common air, introduced from the mercurial
airholder into an exhaufled globe, increafed it
in weight 44.75 grains ; thermometer being
51°, and atmofpheric prefTure 30,7-
106 cubic inches, of fimilar compofition,
weighed in like maimer, gave at the fame tem-
perature and prefTure nearly 52,25 grains ; and
in another experiment, when the thermometer
was 41», 53 grains.
So that accounting for the fmall quantity of
( 95 )
common air contained in the gafes weighed, we
may conclude, that 100 cubic inches of pure
nitrous oxide weigh 50,1 grains at temperature
50^, and atmofphcric preffure 37.
I was a little furprifed at this great fpecific
gravity, particularly as I had expelled, from
Dr. Prieftley's obfervations, to find it lefs heavy
than atmofpherical air. This philofopher fup-
pofed, from fome appearances produced by the
mixture of it with aeriform ammoniac, that it
was even of Icfs fpecific gravity than that gas.*
V. Analyfts of Nitrons Oxide,
The nitrous oxide may be analifed, either by
charcoal or hydrogene ; during the combuflion
of other bodies in it, fmall portions of nitrous
acid are generally formed, as will be fully ex-
plained hereafter.
The gas that I employed \vas generated from
* Experiments and Obfervations, vol. 2, pag, 89. LnJR;
Edition,
( 96 )
compact nitrate of ammoniac, and was in lis
higheft (late of purity, as it left a refiduum of
38 only, when abforbed by boiled water.
30 cubic inches of it were inferted into ajar
graduated to ,1 cubic inches, containing dry
mercury. Through this mercury a piece of
charcoal which had been deprived of its hydro-
gene by long expofure to heat, weighing about
a grain, was introduced, while yet warm: No
perceptible abforption of the gas took place.*
Thermometer being 46°, the focus of a Isns
was thrown on the charcoal, which inftantly
took fire, and burnt vividly for about a minute,
the gas being incrcafed in volume. After the
vivid combuftion had ceafed, the focus was
again thrown on the charcoal ; it continued to
burn for near ten minutes, when the procefs
{lopped.
The gas^ when the original prefTure and tem-
perature were reftorcd, filled a fpace equal to
12,5 cubic inches.
" A minute quantity, however, muft have been abforbed,
and given out again when the charcoal was heated.
( 97 )
On introducing to it a fmall quantity of
ilrong folution of ammoniac*', white vapor
was inftantly perceived, and after a fhort time
the redu6\ion was to about 10,1 cubic inches; Co
that apparently, 2,4 cubic inches of carbonic
acid had been formed. The 10,1 cubic inches
of gas remtlining vvere expofed to water which
had been long in ebullition, and which was
introduced whilft boiling, under mercury.
After the abforption of the nitrous oxide
by the water, the gas remaining was equal to
5,3.
But on combining a cubic inch of pure nitrous
oxide with fome of the fame water, which had
been received under mercury in a feparate veffel,
nearly - remained. Cpnfequently we luay
conclude, that 5,1 of a gas unabforbable by
water, was produced in the combullion.
This gas extinguifhed flame, gave no dimi-
nution with oxygene, and the flightefl: poffible
* Strong foliUion of ammoniac has no attia6tion for
nitrous oxide.
( 98 )
with nitrous gas. When, an eledlrlc fpark was
paflecl through it, mingled with oxygene ; no
inflammation, or percepiible diminution took
place. 'J^ We may confequently conclude that
it was nitrogene, mingled with a minute por-
tion of common air, expelled from the water.
The charcoal was diminifhed in bulk to one
half nearly, but the lofs of weight could not
be afcertained, as its pores were filled with
mercury.
Now 5 cubic inches of nitrous oxide were
ablbrbed by the water, confequently 5 were
decompounded by the charcoal ; and thefe pro-
duced 5,1 cubic inches of nitrogene; and by
giving their oxygene to the charcoal, apparently
2,4 of carbonic acid.
But 5 cubic inches of nitrous oxide weigh 2,5
grains, and 5,1 cubic inches of nitrogene 1,55 ;
then 2,5 — 1,55 = ,95.
So that reafoning from the relative fpecific
I The gas was examined by thofe tells in order to prove
that no water had been decompofed.
( &9 )
gravities of nitrogene and nitrous otide, 2,5
grains of the laft are compofed of 1,55 nitro-
gene, and ,95 oxygene.
But from many experiments made on the
fpecific gravity of carbonic acid, in Augutl,
179P, I concluded that 100 cubic inches of it
weighed 47,5 grains, thermometer being 6o,l°a
and barometer 29,5. Confequently, making
the neceflary correflions, 2,4 cubic inches of
it weigh IjM grains; and on Lavoifier's and
Guyton's * eftimation of its compofition, thefe
1,13 grains contain 8,2 of oxygene.
So that, drawing conclulions from the quan-
tity of carbonic acid formed in this experiment,
2,5 grains of nitrous oxide will be compofed of
,82 oxygene, and 1,68 nitrogene.
The difference between ihefe eftimations is
confidcrable, and yet not more than might
have been expelled, if vveconfider the probable
fog rces of error in the experiment.
* See the curious paper of this excellent philofopber, on
the combuftion of the diamond, in which he proves that
charcoal is, in fa«5^, o:udp of diamond. Anijaks de Gbicnie,
( 100 )
1. It is likely that variable minute quan-
tities of h} drogcne remain combined with char-
coal, even after it has been long expofed to a
red heat.
2. It is probable that the nitrogene and car-
bonic acid produced were capable of diflblving
more water than that held in folution by the ni-
trous oxide ; and if fo, they were more condenfed
than if faturated with moiflure, and hence the
quantity of carbonic acid under-rated.
We may conlequently fuppofe the eflimation
founded on the quantity of nitrogene evolved,
moft corredl ; and making a fmall allowance
for the difference, conclude, that 100 grains
of nitrous oxide are compofed of about 37
oxygene, and 63 nitrogene ; exifting in a much
more condenfed ftate than when in their fimplc
forms.
The tolerable accuracy of this ftatement will
be hereafter demonflrated by a number of expe-
riments on the combuftion of different bodies
in nitrous oxide, detailed in Refearch II.
(101)
VI. Minute examination of the decompofttion of
Nitrate of Ammoniac.
Into a retort weighing 413,75 grains, and
of the capacity of 7,5 cubic inches, 100 grains
of pulverifed compa6l nitrate of ammoniac were
introduced. To the neck of this retort was
adapted a recipient, weighing 7 1 1 grains, tubu-
lated for the purpofe of communicating with
the mercurial airholdcr, and of the capacity of
8,3 cubic inches.
Temperature being 50^, and atmofpheric
preflTure 30,6, the recipient was inferted into a
vefTel of cold water, and made to communicate
with the airholder. The heat of a fpirit lamp
was then flowly applied to the retort : the fait
quickly began to decompofe, and to liquify.
Tl^e temperature was fo regulated, as to keep
up an equable and flow decompofition.
During this decompofition, no luminous
appearance was perceived in the retort; the
gas that came into the airholder was very little
( 102 )
clouded, and much water condenfed in the
receiver.
After the procefs was finifhed, the commu-
nication between the mercurial airholder and
the recipient was preferved till the common
temperature was reftored to the retort.
The volume of the gas in the cylinder was
85,5 cubic inches. The abfclute quantity of
nitrous oxide in thofe 85,5 cubic inches, it was
difficult to afcertain with great nicety, on ac-
count of the common air previoufly contained
in the vefTels.
45 meafures of it, expofed to well boiled
water, diminifhed by agitation to 8 mea-
fures. So that reafoning from the quan-
tity of air, which fhould have been expelled
from the water by the nitrous oxide, we may
conclude that the 85,5 cubic inches were nearly
pure.
The retort now weighed 419,25 grains, con-
fcqucntly 5,5 grains of fait remained in it.
This fait was chiefly colledled about the lower
part of the neck, and contained rather more
( 103 )
water than the compadl nitrate, as in fome
places it was cryftalifed.
The recipient with the fluid it contained,
Vveighed 75g grains. ' It had confeqiiently
gained in weight 48 grains.
Now the 85,5 cubic inches of nitrons oxide
produced, weigh about 42,5 grains; and this ad-
ded to 48 and 5,5, = 96 grains ; fo that about 4
grains of fait and fluid were loft, probably by
being carried over and depofited by the gas.*
As much of the fluid as could betaken out of
the recipient, weighed 46 grains, and held in fo-
lution much nitrate of ammoniac with fuper-
abundance of acid. This acid required for its
faturation, 3 - of carbonate of ammoniac (con-
taining, as well as I could guefs), about 20 per
cent alkali.
The whole folution evaporated, gave 18
grains of compadl nitrate of ammoniac. But
*This was adually the cafe; for on examining the con-
ducing tube the day after the CKperiment, fome minute
cryftals of prifiuatic nitrate of ammoniac were perceived
in it.
( 104 )
rcafoning from the quantity of carbonate of
ammoniac employed, the free nitric acid was
equal to 2,^5 grains, and this muft have formed
3,56 grains of fait. Confequently the fait pre--
exifting in the folution was about 14,44 grains.
Bat befides the fluid takeri out of the recipient,
2 grains remained in it : let us fuppofe this^
and the 4 grains loft, to contain 2 of fait, and
.6 of free acid.
Then the undecompounded
fait is 5,5 + 14.4 + 2 = 21,9
The free acid 2,75 + ,6 = 3,35
Gas - . - 42,5
Water ^ - ^ 32,25
]00
Now about 76,1 grains of fait were decom-
pounded, and formed into 42.5 grains of gas,
3,35 grains acid, and 32,25 grains water.
But there is every reafon to fuppofe, tli^it iq
this procefs, when the hydrogene of the ammo-
niac combines with a portion of the oxygene of
the nitric acid to form water, and the nitrogenc
( 105 )
enters into union with the nitrogene and re-
maining oxygene of the nitric acid, to form
nitrous oxide ; that water pre-exifting in nitric
acid and ammoniac, fuch as they exifted in
the aeriform ftate, is depolited with the water
produced by the new arrangement, and not
wholly combined with the nitrous oxide formed.
Hence it is impoffible to determine with great
exactitude, the quantity of water which was
abfolutely formed in this experiment.
78,1 grains of fait are compofed of 15,4
alkali, 58 acid, and 4,7 water.
And reafoning from the different affinities of
water for nitric acid, ammoniac, and nitrous
oxide, it is probable that ammoniac, in its de-
compofition, divides its water in fuch a ratio,
between the nitrogene furniflied to the nitrous
oxide, and the hydrogene entering into union
with the oxygene of the nitric acid, as to enable
us to affume, that the hydrogene requires for
its faturation nearly the fame quantity of oxy-
gene as when in the aeriform tlate ; or that it
certainly cannot require lefs.
( loS )
But 15,4 alkali contain 3^08 hydrogene, and
12,32 nitrogene ;* and 3,08 hydrogene require
17,4 of oxygene to form 20,48 of water.
Now 32,5 grains of water exifted before the
experiment ; 4,7 grains of water were con-
tained by the fait decompofed, and 32,5 — 4,7
=z 27,8 : and 27,8 — 20,48, the quantity gene-
rated, = 7^52, the quantity cxifting in the nitric
acid.
But the nitric acid decompofed is 58^ — 3,35
= to 54,7 ; and 54,7 — 7-5 = 47,2, which
entered into new combinations. Thefe 47,2
confift of 33,2 oxygene, and 14, nitrogene.
And 33,2 — 17,4, the quantity employed to
form the water, = 15,8, which combined with
14„ nitrogene of the nitric acid, and 12,32
of that of the ammoniac, to form 42,12 of
nitrous oxide. And on this eflimation, 100 parts
of nitrous oxide would contain 37,6 oxygene,
and 62,4 nitrogene ; a computation much
nearer the refults of the analyfis than could
* Owing part of their weight to an unknown quantity
of water.
( 107 )
have been expected, particularly as fo many
unavoidable fources of error exifted in the
procefs.
The experiment that I have detailed is the
mod accurate of four, made on the fame quan-
tity of fait. The others were carried on at
rather higher temperatures, in confequence of
which, more water and fait were fublimed with
the gas.
To Berthollet^ we owe the diTcovery of the pro*
dudts evolved during the flow decompofition of
nitrate of ammoniac; but as this philofopher
in his examination of this procefs, chiefly de-
figned to prove the exiftence of hydrogene in
ammoniac, he did not afcertain the quantity of
gas produced, or minutely examine its proper-
ties ; from two of them, its abforption by water
and its capability of fupporting the vivid com-
buftion of a taper, he inferred its identity with
the dephlogifticated nitrous gas of Prieftley, and
concluded that it was nitrous gas with excefs
of pure air.*
*Mem. de Paris. 1785;, and Journal de Phyfique, 1/80,
page 175.
( 108 )
VIL Of the heat produced during the decom*
fofition of nitrate of ammoniac.
To afccrtain whether the temperature of
nitrate of ammoniac was increafed or diminifhed
after it had been raifed to the point elTential to
its decompofition, during the evolution of ni-
trous oxide and water ; that is, in common lan-
guage, whether heat was generated or abforbed
in the procefs ; I introduced a thermometer into
about 1500 grains of fibrous nitrate of ammo-
niac, rendered liquid in a deep porcelain cup.
During the whole of the evaporation, the tem-
perature was about 380*", the fire being care-
fully regulated.
As foon as the decompofition took place, the
thermometer began to rife ; in lefs than a quar-
ter of a minute it was 410^, in two minutes it
was 460°,
The cup was removed from the fire ; the de-
compofition flill went on rapidly, and for about
a minute the thermometer was flationary. It
( i09 )
then gradually and flowly fell ; in three minutes
it was 440*', in five minutes 420^, in feven
minutes 405°, in nine minutes 36o°, and in
thirteen minutes 307°, when the decompofition
had nearly ceafed, and the fait began to folidify.
From this experiment, it is evident that an
increafe of temperature is produced by the
decompofition of nitrate of ammoniac : though
the capacity of water and nitrous oxide for
heat, fuppofing the truth of the common doc-
trine, and reafoning from analogy, mull be
confiderably greater than that of the fait.
VIII. Of the decompofition of Nitrate of Am-
moniac at high temperatures^ and produBion of
Nitrous gas ^ Nitrogene^ Nitrous Acid, and Water.
At an early period of my inveftigation relating
to the nitrous oxide, I difcovered that when a
heat above 600° was applied to nitrate of ammo-
niac, fo that a vivid luminous appearance was pro-
duced in the retort, certain portions of nitrous
gas, and nitrogene, were evolved with the
(110)
nitrous oxide. But I was for fome time igna-
rant of the precife nature of this decompofition^
and doubtful with regard to the poflibility of
effedting it in fuch a manner as to prevent the
produ61ion of nitrous oxide altogether.
I firfi: attempted to decompofc nitrate of
ammoniac at high temperatures, by introducing
it into a well coated green glafs retort, having
a wide neck, communicating with the pneu-
matic apparatus, and ftrongly heated in an air-
furnace. But though in this procefs a detona-
tion always took place, and much light was pro-
duced, yet fiill the greater portion of the gas
generated was nitrous oxide ; the nitrous gas
and nitrogene never amounting to more than
one third of the whole.
After breaking many retorts by explotions,
without gaining any accurate refults, I em-
ployed a porcelain tube, curved fo as to be
capable of introduction into the pneumatic
apparatus, and clofed at one rnd.
The clofed end was heated red, nitrate of
ammoniac introduced into it, and all the latter
( 111 )
portions of gas produced in the explofion, re-
ceived in the pneumatic apparatus, filled with
warm water.
Three cxplofions were required to fill a jar
of the capacity of 20 cubic inches. The gas
produced in the firft, when it came over, was
tranfparent and dark orange, fimilar in its
appearance to the nitrous acid gas produced in
the firfl experiment ; but it fpeedily became
white and clouded, whilft a flight diminution
of volume took place.
When the fecond portion was generated and
mingled with the clouded gas, it again became
tranfparent and yellow for a fliort time, and then
affumed the fame appearance as before.
The water in the trough, after this experi-
ment, had an acid tafte, and quickly red-
dened cabbage juice rendered green by an
alkali
6 cubic inches of the gas produced were
expofed to boiled water, but little or no abforp-
tion took place. Hence, evidently, it con-
tained no nitrous oxide.
( 112 )
They were tlien expofed to folution of ful-
phate of iron : the folution quickly became dark
colored, and an abforption of 1,6 took place
on agitation.*
The gas remaining inftantly extinguifhed the
taper, and was confequently nitrogene.
^ This experiment was repeated, with nearly
the fame refults.
We may then conclude, that at high tem-
peratures, nitrate of ammoniac is wholly re-
folved into water, nitrous acid, nitrous gas,
and nitrogene ; whilft a vivid luminous appear-
ance is produced.
/ The tranfparency and orange color produced
in the gas that had been clouded, by new por-
tions of it, doubtlefs arofe from the folution of
the nitric acid and water forming the cloud, in
% the heated nitrous vapor produced, fo as to con-
ftitute an aeriform triple compound ; whilft the
cloudinefs and abforption fubfcquent were pro-
^' The abforption of nitrous gas by fulphate of iron^ kc
will be treated of in the next cUvifion.
{ 113 )
duced by the diminiftied temperature, which
deflroyed the ternary combination, and feparated
the nitrous acid and water from the nitrous
gas.
From the rapidity with which the deflagra-
tion of nitrate of ammoniac proceeds, and from
the immenfe quantity of light produced, it is
reafonable to fuppofe that a very great in creafe
of temperature takes place. The tube in which
the decompofition has been efFeded, is always
ignited after the procefs.
IX. Speculations on the decompojitions of
Nitrate of Ammoniac,
All ■ the phsenomena of chemillry concur in
proving, that the affinity of one body, A, for
another, B, is not deftroyed by its eombinatioa
with a third, C, but only modified ; either by
condenfation, or expanfion, or by the attra6lion
of C for B.
On this principle, the attraction of compound
bodies for each other mufl be revolved into the
H
( 114. )
reciprocal atlraflions of their cotiftituents, and
conlequeotly the changes produced in them by
variations of tem|>erature eipblned, from the
alteratioas prodoced in the attradions of thofc
coniiit!icnts.
Thus in nitrate of ammoniac^ four affioltics
may be fappofed to exill :
1* That of hydrogeoe for nitrogenCj produ-
clng ammoniac.
2. That of oxygeoe for nitrous gas, prodocing
nitric acid.
3* That of the hydrogeoe of ammoniac for the
oxygeae of nitric acid.
A. That of the oitrogcnc of ammoniac for
the nitrous gas of nitric acid.
At temperatures bdow 300% the felt, from
the eqoilibriam between thefe affioilies, prc-
ferves its exifencc.
Now when its temperature is raifcd io 400%
tlieattradiions of hydmgene for nilTOgene,*aiid
* As ifi evident from the decompolition of ammoniac bv
keat.
( ^1^ )
of nitrous gas for oxygen c,:|: are climini(hed s;
whilfl the atlradlion of hydrogene for oxygencf"
is increafed; and perhaps that of nitrogene for
iiitrous gas.
Hence the foi'mer equilibrium of affinity is
deftroyed, and a new one produced.
The hydrogene of the ammoniac combines
with the oxygefie of the nitric acid to generate
water ; and the nitrogene of the ammoniac
enters into combination with the nitrous gas
to form nitrous oxide : and the water and ni-
trous oxide produced^ mod probably exifl; in
binary combination in the aeriform flatc, at the
temperature of the dccompofition.
But when a heat above 800° is applied to
nitrate of ammoniac, the attradtions of nitro-
gene and hydrogene for each other, and of
• :;: Nitric acid is phlogifticated by heat, as appears from
Dr. Prieftlcy's experiments. Vol. 3, p. 26.
t As is evident from the increafe of temperattire fe<|uiT^"
for the formation of water.
(li6)
oxygene for nitrous gas,* are ftill more dimi-
nifhed ; whillt that of nitrogene for nitrous gas
is deflroyed, and that of hydrogene for oxy-
gene increafed to a great extent : likevvife
a new attraiiion takes place; that of nitrous
gas for nitric acid, to form nitrous vapor.-^
Hence a new arrangenient of principles is
rapidly produced; the nitrogene of ammoniac
*^- For ammoniac and nitrous oxide arc both decompofcd at
the red heat, and oxygene given out from nitric acid when
it is paffed through a heated tube.
f Whenever iiitrous acid is produced at high tempera-
tures, it is always highly phlogifticated, provided it has not
been long in conta6t with oxygene. When Dr. Prieftley
pafled nitric acid through a tube heated red, he procured
much oxygene, and phlogifticated acid j and the water
in the apparatus employed was fully impregnated with
nitrous air. Hence it would appear, that heat diminilhes
the attra6tion between oxygene and nitrous gas, and in-
creafes the affinity of nitrous gas for nitrous acid. Mr.
James Thomson, whofe theory of the Nitrous Acid 1 have
already mentioned, from fome experiments on the phlo-
giftication of Nitric Acid by heat, which he has commu-
nicated to me, concludes with great juftnefs, that a portion
of the acid is always completely decompofed in this procefs:
^he oxygene liberated, and the nitrous gas combined with
the remaining acid.
( li7 )
having no affinity for any of the fingle principles
at this temperature, enters into no binary com-r
pound : the oxygene of the nitric acid forms
water with the hydrogene, and the nitrous gas
combines with the nitric acid to form nitrous
vapor. All thefe fubftances moft probably
exift in combination at the temperature of their
production ; and at a lower temperature, affume
the forms of nitrous acid, nitrous gas, nitrogene,
and water.
I have avoided entering into any difcuffions
concerning the light and heat produced in this
procefs ; becaufe thefe phsenomena cannot be
rcafoned upon as ifolated fafls, and their relation
to general theory will be treated of hereafter.
X. On the preparation of Nlirous Oxide for
experiments on Refpiration,
When compac-l nitrate of ammoniac is ilowly
decompofed, the nitrous oxide produced is
almoft immediately fit for refpiration ; but as
Qne part of the fait begins to decompofe befor?;
\
/
( 118 )
the other is rendered fluid, a confiderable lofs is
produced by fublimation.
For the produflion of large quantities of
nitrous oxide, fibrous nitrate of ammoniac (hould
be employed. This fait undergoes no decom-
pofitioh till the greater part of its water is evapo-
rated, and in confequence at the commencement
of that procefs, is uniformly heated.
The gas produced from fibrous nitrate, muft
be fufFered to reft at leaft for an hour after it$
generation. At- the end of this time it is gene-
rally fit for refpiration. If examined before, it
will be found to contain more or lefs of a white
yapor, which has a difagreeable acidulous tafte,
and ftrongly irritates the fauces and lungs. This
yapor, mod probably^ confifts of acid nitrate
of ammoniac and water, which were diflblvcd
by the gas at the temperature of its production,
and afterwards flowly precipitated.
It is found in lefs quantity when compact
nitrate is employed, becaufe more fait is fub-
limed in this procefs, which being rapidly pre-
cipitated, carries with it the acid and water.
( 1^9)
Whatever fait ss employed;, the laft portions
of gas produced, generally contain leis vapor,
jjnd may in confequence be refpired icK>ner tbad
the firll.
The nitrate of ammoniac fhould never be
decompofed in a metallic veflel,* nor the gas
produced fuffcred to come in conta<5i with
any metallic furface ; for in this caie the free
nitric acid will be decompofed, and in conse-
quence, a certain quantity of nitrous gas pro-
duced. ^
The apparatus that has been generally em-
ployed in the medical pneumatic infiitution, for
the produ6iion of nitrous oxide, confifts
3 . Of a glafs retort, of the capacity of two or
three quarts, orificed at the top, and furnifhed
with a ground ftopper.
2. Of a glafs tube, conical for the purpole
of receiving the neck of the retort ; about ,4
inches wide in the narrowed part, 4 fett long,
curved at the extremity, fo as to be capable of
"*• Except it be gold or piatina.
( 120 )
Introdudlion into an airholder, and inclofed by
tin plate to preferve it from injury.
3J Ofairholders of Mr. Watt's invention^,
filled with water faturated with nitrous oxide.
4. Of a common air-furnace, provided with
dampers for the regulation of the heat.
The retort, after the infertion of the fait, i^
connected with the tube, carefully luted, and
expofed to the heat of the furnace, on a con-
venient (land. The temperature is never fuf-
fered to be above 500°. After the decompofi-
tion has proceeded for about a minute, fo that
the gas evolved from the tube enlarges the
flame of a taper, the curved end is inferred
into the airholder, and the nitrous oxide pre-
ferved.
The water thrown out of the airholders in
confequence of the introduction of the gas,
is prcfervcd in a veiicl adapted for the pur-
pofe, and employed to fill them again ; for if
common water was to be employed in every es^-^
periment, a great lofs of gas would be produced
from abforption.
( 121 )
A pound of fibrous nitrate of ammoniac, do-
compofed at a heat not above 500^, produces
nearly 5 cubic feet of gas ; whilft from a pound
pf compadl nitrate of ammoniac, rarely more
than 4,25 cubic feet can be collccled.
For the production of nitrous oxide in quan-
tities not exceeding 20 quarts, a mode ftill
more fimple than that I have juft defcribed may
be employed. The fait ipay be decompofed by
the heat of an argands lamp, or a common fire,
in a tubulated glafs retort, of 20 or 30 cubic
inches in capacity, furnifhed with a long neck,
curved at the extremity ; and the gas received
in fmall airholders.
Thus, if the pleafurable efFeds, or medical
properties of the nitrous oxide, (liould ever
make it an article of general requefl:, it may be
procured with much lefs time,, labor, and
expence,* than mofl of the luxuries, or even
necefTaries, of life.
* A pound of nitrate of ammoniac cofts about 5s. lOd.
This pound, properly decompofed, produces rather more
than 34 moderate dofes of air j fo that the expence of a
dofe is about 2d. What f.uid ftimulus can be procured at
fo cheap a rate ?
IJMMUmlUl — - .J.t.H—W»iPBI—MH I ll^m
ravisioN IV,
EXPERIMENTS and OBSERVATIONS en ibe
COMPOSITION (?/ NITROUS GAS, and on iis
ABSORPTION hy drffcrcst hodm.
I. Prelimmarks,
In my account of the compofition of nitric
scid, in Diviiion I. I gave an eftimation o{ the
qnanlities of oxygene and nitrogene combined
2^1 nitrons gas : I fhall now detail the experi-
ments on which that eitimation is founded.
At an early period of my refearches relating
to nitrous oxide, from the obfcrvation of the
pha^nomena taking place during the produ^iion
of this fubftance, I had concluded, that the
common opinion with regard to the compofition
of nitrous gas, was very diftant from the
troth. I had indeed analyfed nitrous gas^ by
converting it into nitrous oxide, before I at-
( 1^3 )
tempted to afcertain its compofition by imme-
diately feparating the conftitucnt principles from
each other : and my firft hopes of the poffi-
bility of efFetSling this, were derived from Dr.
Prieftley*s experiments on the combufllon of
pyrophorus in nitrous gas, and On the changes
cfFedled in it, by heated iron and charcoal.
This great philofopher found, that pyropho-
rus placed in contadl with nitrous gas, burnt
with great vividnefs, whilfl the gas was dimin-
iflied in volume to about one half, which gene-
rally confifted of nitrogene and nitrous oxide.*
He likewife found, iron heated by a lens in
nitrous gas, increafed in weight, whilft the
gas was diminfhed about -|, and converted into
nitrogene.*
He heated common charcoal, and charcoal
of copper,^ in nitrous gas by a lens. When
* Experiments and Obfervations, vol. ii. pag. 50. Laft
Edition.
X That is, charcoal produced by the deconfipofition of
Cpirits of wine. Vol. 11. pag. 3p.
( 124 )
common charcoal was employed, the gas was
neither increafed or diminifhed in bulk, but
wholly converted into nitrogene ; when char-
coal of copper was ufed, the volume was a little
increafed, and the gas remaining confifted
of- nitrogene, and - carbonic acid.
In his experiments on the iron and pyrophy-
rus, the nitrous gas was evidently decompofed.
From the great quantity of nitrogene produced
in thofe on the charcoal, it feems likely that both
the common charcoal,* and the charcoal of
copper employed contained atmofpherical air,
which being difpelled by the heat of the lens.
* Dr. Prieftley fays, " having heated iron in nitrous air^,
" I proceeded to heat in the fame air, a piece of charcoal
" not long after it had been fubjedcd to a ftrong heat covered
" with fand. The fan not (hlning immediately, after th«
"' charcoal \yas introduced into the veflel of air, through the
" mercury by which it was confined, part of the air was
••' abforbed j'but on heating the charcoal, the quantity was
'' increafed. Having continued the progrefs as long as I
'' thought neceflary, I examined the air and found it to be
'^ about as much as the original quantity of nitrous airj
" but it was all phlogiilicatcd air extingnifhing a candle
" and having no mixture of fixed ^ir in it."- — Experiments
snd Obfervations, Vol. II, page Sp.
( 125 )
was decompofed by the nitrous gas : indeed,
till I made the following experiment, I fufped^cd
that the carbonic acid produced, when the char-
coal of copper was employed, a role from a dc-
compofition of the nitrous acid, formed in this
way,
I introduced a piece of well-burnt charcoal,
which could hardly have weighed the eighth of
a grain, whilft red hot, under a cylinder filled
with mercury, and admitted to it half a cubic
inch of nitrous gas. A flight abforption took
place.
The fun being very bright, I kept the char-
coal in the focus of a fmall lens for near a quar-
ter of an hour. At the end of this time the gas
occupied a fpace nearly as before the experi-
ment, and a very minute portion of the charcoal
had been confumed. On introducing into
the cylinder a fmall quantity of iblution
of ftrontian, a white precipitation was per-
ceived, and the gas ilovvly diminifhed to
about three tenths of a cubic inch. To thefc
( 126 )
three tenths a little commoa air was adinittect
when very flight red fumes were perceived.
This experiment convinced me, that the at-
tradlion of charcoal for the oxygene of nl^'
trous gas, at high temperatures, was fuffi-
ciently ftrong to efFedt a flow decompofition of
it.
To be more accurately acquainted with this
decompofition, and to learn the quantities of
carbonic acid and riitrogene produced from a
known quantity of nitrous gas, I proceeded in
the following manner.
11. Analyfis of Nitrons Gas hy Charcoal,
A quantity of nitrous gas was procured in a
water apparatus, from the decompofition of
nitrous acid hy mercury. A portion of it was
transferred to the mercurial trough. After the
mercury and the jar had been dried by bibulous
paper, 40 meafures of this portion were agitated
in a folution of fulphate of iron. The gas re-
maining after the abforption was complete.
i m )
filled aboat a meafure asid half; fo that tlie
mtroas gas contained nearly ^ iiitrogene.
•Tl3crmo25icter being 53®5 a fi«ail piece of
ii'ell borot charcoal, the weight of which coiiiA
I'iardly have equalled a <|uarler of a graio, was
Introdaccd Ignited^ into a fmall cyiiader filled
with mercury^ graduated to ^ iO gmia meiifurcto;
to this, l5 meafarfiSj equal to i6D grain m. af
introjLss gas, were admitted- An abforption of
Siboiit OQC aieafure aad half took place. When
the ^ciis of a lens was thrown on the charco^l^
a flight increafe of the gas was prcdiiccd^ from.
the emiffioe of that which had been shforhod.
Aftcr.the proccls had bcca carried ois for^hmit
3L half aa hour^ the charcoal evidcotlj bcgaai
to famCf and to canfame ¥erv fiawh^j ihoiigh
HO alteration in the volisme of the gas was ob~
feri^ed-
Tfce fun i3ot conflanlly fliinlng, ihc progrcH
of the experiment was now aiad iheij ft0p|jed .:
but taking the ^hole timc^ the focMS could n^t
hare hecn applied to it for lefn than foiir Lonm.
Whca the procels was firiillicd, the gas wm
( 1^8 )
increafed in bulk nearly three quarters bf d
ineafure.
A drop of water was introduced into
the cylinder, by means of a fmall glafs
tube, on the fuppofition that the carbonic acid,
and nitrogene, might be capable of holding
in folution, more water than that contained
in the nitrous gas decompofed ; but no
alteration of volume took place.
When 20 graiti meafures of folution of pale
green* fulphatc of iron were introduced into the
cylinder^ they became ratherycllovver than before,
but not dark at the edges, as is always the cafe
when nitrous gas is prefent. On agitation, a
diminution of nearly half a meafure was pro-
duced, doubtlefs from the abforption of fomc
of the carbonic acid by the folution.
A fmall quantity of cauftic potafh, much
more than was fufficient to decompofe the fiil-
phate of iron, was now introduced. A rapid
diminution took place, and the gas remaining
* That is, fulphate of iron containing oxide of iron, in the
lirft degree of oxygenation.
( lig)
filled about 8 meafiires. This gas was agitated
for fome time over water, but no abforption
took place. Two itieafures of it were then
transferred into a detonating cylinder with two
meafures of oxygene. The electric fpark was
pafTed through them, but no diminution was pro-
duced. Hence it vvas nitrogene, mingled with
no afcertainable quantity of hydrogene : con-
fequently little or no water could have been
decompofed in the procefs.
Now fuppofing, for the greater eafe of calcu-
lation, each of the meafures employed, cubic
inches.
16 of nitrous gas — ^q ==== ^^A were decom-
pofed, and thefe weigh, making the neceflary
corrections, 5,2 ; but 7,4 nitrogene were pro-
duced, and thefe weigh about 2,2. So that
reafoning from the relative fpecific gravities of
nitrous gas and nitrogene, 5,2 grains of nitrous
gas will be compofed of 3 oxygene, and 2,2
nitrogene.
But 8,7 of carbonic acid were produced,
which weigh 41 grains, and confift of 2,9 oxy-
I
( 130 )
g;enje, and 1,2 charcoal. * Conrecjuently,
drawing conclulions from the quantity of car-
bonic acid formed, 5,2 grains of nitrous gas
will confift of 2,9 oxygene, and 2,3 nitrogene.
The difference in thefe edimations is ranch
Jefs than could have been expe61ed ; and taking
the mean proportions, it would be inferred
from them, that 100 grains of nitrous gas, con-
tain 56,5 oxygene, and 43.5 nitrogene.
I repeated this experiment with refults not
very different, except that the increafe of
volume was rather greater, and that more
unabforbable gas remained ; which probably
depended on the decompofition of a minute
quantity of water, that had adhered to the
charcoal in pafling through the mercury.
As nitrous gas is decompofable into nitrous
acid, and nitrogene, by the eledlric fpark ; it
occurred to me, that a certain quantity of
nitrous acid might have been pofRbly produced,
in the experiments on the decompofition of
nitrous gas, by the intcnfely ignited charcoal.
•* That iS; carbori; or oxide of diamond.
( 131 )
To afcertain this circumftance, I introduced
into VI meafures of nitrous gas, a fmall piece
of charcoal which had been jutt reddened.
The fun being very bright, the focus of the
lens was kept on it for rather more than an
hour and quarter. In the middle of the procefs
it began to fume and to fparkle, as if in com-
buftion. In three quarters of an hour, the
gas was increafed rather more than half a
mcafure; bnt no alteration of volume took
place afterwards.
The mercury was not white on the top as is
ufually the cafe when nitrous acid is produced.
On introducing into the cylinder a little pale
green fulphate of iron, and then adding prufiate
of potafh, a white precipitate only was produ-
ced. Now, if the minuteft quantity of
nitric acid had been formed, it would have
been decompofed by the pale green oxide of
iron, and hence, a vifible quantity of pruffian
blue* produced^ as will be fully explained here-
after.
* That is, blue prufTiate of iron.
( 15^^ )
III. Analyfis of Nitrous Gas by PyrophoTtis*
I placed fome newly made pyrophorus, about
as much as would fill a quarter of a cubic
inch, into a jar filled with dry mercury, and
introduced to it, four cubic inches of nitrous
gas, procured from mercury and nitric acid.
It inftantly took fire and burnt with great
vividnefs for fome moments.
After the combuftion had ceafed, the gas
was diminifhed about three quarters of a cubic
inch. The remainder was not examined ; for
the diminution appeared to go on for fome
time, after ; in an half hour, when it was com-
pleat, it was to 2 cubic inches. A taper,
introduced into thefe, burnt with an enlarged
flame, blue at the edges ; from whence it
appeared, that they were compofed of nitrogene
and nitrous oxide.
I now introduced about half a cubic inch of
pyrophorus to two cubic inches of nitrous gas ;
the combuftion took place, and the gas was
( 133 )
rapidly diminiflied to one half; and on fufFering
it to remain five minutes to one-third nearly ;
which extinguifhed flame.
Sufpedling that this great diminution was
owing to the abforption of fome of the nitro-
gene formed, by the charcoal of the pyrophorus,
I carefully made a quantity of pyrophorus;
employing more than two-thirds of alumn, to
one-rthird of fugar.
To rather more than half of a cubic inch of
this, two cubic inches of nitrous gas, which
contained about ~ nitrogene^ were admitted.
After the combuftion, the gas remaining, aj}pa'
rently filled a fpace equal to 1,2 cubic inches;
but, as on account of the burnt pyrophyrus in
the jar, it was impoilible to afcertain the volume
with nicety, it was carefully and wholly trans-
ferred into another jar. It filled a fpace equal
to 1,15 cubic inches nearly.
When water was admitted to this gas no
abforption took place. It underwent no dimi-
nution with nitrous gas, and a taper plunged
into it was iniiantly extinguifhed. We may
confequcntly conclude that it was nitrogene.
( 134 )
Now 2 cubic inches of nitrous gas weigh
^686 grains, and 1,1 of nitrogene — ,05^
the quantity previoufly contained in the gas
= to 1,05, 3,19. Hence ,686 of nitrous gas
would be compofed of ,367 oxygene, and ,319
nitrogene ; and 100 grains would contain 53,4
oxygene, and 46^6 nitrogene.
IV. Additional obfervations on the comhiftion
of bodies in Nitrous GaSy and on its Compoji-
iion.
Though phofphorus may be fufed, and even
fublimcd, in nitrous gas, without producing
the ilightelt luminous appearance,* yet when
* No luminous appearance is produced w hen phofphorus
is introduced into pure nitrous gas. It has been often ob-
ferved, that phofphorus is luminous in nitrous gas, that has
not been long in conta<!it with water after its produftion.
This phaenomeaon, I fufpcd, depends either on the decom-
petition of the nitric acid held in folution by the nitrous
gas i or on the combination of the phofphorus with oxygene
loofely adhering to the binary aeriform compound of nitric
acid and nitrous gas. 1 have not yet examined if nitrous
gas can be converted into nitrous oxide by long expofure
to heated phofphorus : it appears, however, very probable.
( 135 )
it is introduced into it in a ftate of adive in-
flammation, it burns with almoft as much
vividnefs as in oxygene.^ Hence it is evident,
that at the heat of ignition, phofphorus is
capable of attradling the oxygene from the
nitrogene of nitrous gas.
I attempted to analife nitrous gas, by intro-
ducing into a known quantity of it, confined
by mercury, phofphorus, in a veffel containing
a minute quantity of oxygene.'}- The phofpho-
rus was inflamed with an ignited iron wire, by
which, at the moment of the combuftion, the
vefl^l containing it was raifed from the mercury
into the nitrous gas. But after making in this
way, five of fix unfuccefsful experiments, I
defifted. When the communication between
the veflels was made before the oxygene was
nearly combined with the phofphorus, nitrous
■* Perhaps this fad has been noticed before 3 I have not,
however, met with it in any chemical work.
t This mode of inflaming bodies in gafes, not capable of
Tupporting combuftion at low temperatures^ will be par-
ticularly defcribed hereafter.
( 136)
acid was formed, which inftantly deftroyed the
combuftion ; when^ on the contrary, the phof-
phorus was fufFered to confume almoll the
whole of the oxygene, it was not fufficiently
ignited when introduced, to decompofe the
nitrous gas.
In one experiment, indeed, the phofphorus
burnt for a moment in the nitrous gas ; the
diminution however was flight, and not more
than ^of it was decompofed.
Sulphur, introduced in a (late of vivid in-
flammation, into nitrous gas, was inftantly
extinguiflied.
I pafled a ftrong eleflric (hock through equal
parts of hydrogene and nitrous gas, confined by
mercury in a detonating tube ; but no inflani-
mation, or perceptible diminution, was pro-
duced.
1 9,2 grain meafures of hydrogene were fired
by the eledric Ihock, with 10 of nitrous oxide,
and 6 of nitrous gas ; the diminution was to 1 7 ;
and pale green fulphate of iron admitted to the
refiduvim, was not difcolored, Confequently the
( 137 )
nitrous gas was decompofed by the hydrogene,
and as will be hereafter more clearly underftood,
nearly as much nitrogene furnifhed by it, as
would have been produced from half the quan-
tity of nitrous oxide.
Sufpeding that phofphorated hydrogene
might inflame with nitrous gaSj I paffed the
eledlric fpark through 1 meafure of phofphorated
hydrogene, and 4 of nitrous gas ; but no dimi-
nution was perceptible. I likewife pafled the
eledlric fpark through 1 of nitrous gas, with 2
of phofphorated hydrogene, without inflamma-
tion.
Perhaps if I had tried many other difFererlt
proportions of the gafes, I fhould have at laft
difcovered one, in which they would have in-
flamed ; for, as will be feen hereafter, nitrous
oxide cannot be decompofed by the compound
combuftible gafes, except definite quantities arc
employed.
From Dr. Prieftley's experiments on iron and,
pyrophorus, and from the experiments I have
detailed, on charcoal, phofphorus, and hydro-
%
( 138 )
gene, it appears that at certain temperatures,
nitrous gas is decompofable by mofl: of thex:om-
buflible bodies : even the extinflion of fulphur,
when introduced into it in a flate of inflamma-
tion, depends perhaps, on the fmaller quantity
of heat produced by the combuflion of this body,
than that of moil others.
The analyfis of nitrous gas by charcoal, as
0 affording data for determining immediately the
quantities of oxygene and nitrogcne, ought to
beconfidered as moll accurate ; and correcting
it by mean calculations derived from the decom-
pofition of nitrous gas by pyrophorus and hydro-
gene, and its converlion into nitrous oxide, a
procefs to be defcribed hereafter, we may con-
clude, that lOOgrains of nitrous gas are compofed
of 55,95 oxygene, and 44,05 nitrogene; or
taking away decimals, of 56 oxygene, and 44
nitrogene.
This eflimation will agree very well with the
mean proportions that would be given from Dr.
Priefiley's experiments on the decompofition
i>f nitrous gas by iron ; but as he never afcer-
( 139 )
tained the purity of his nitrous gas/* and proba-^
bly employed different kinds in different expe-
riments, it is impoffible to fix on any one, from
which accurate conclusions can be drawn.
Lavoifier's eflimation of the quantities of oxy-
geneand nitrogene entering into the compofition
of nitrous gas, has been generally adopted.
He fuppofes 64 parts of nitrous gas to be com-
pofed of 43^ of oxygene, and 20^ofnitro-
gene.-f-
The difference between this account and
mine is very great indeed ; but I have already,
in Divifion ifl, pointed out fources of error in
the experiments of this great man, on the de-
compofition of nitre by charcoal ; which expe-
riments were fundamental, both to his accounts
of the conftitution of nitrous acid, and nitrous
gas.
* Elements EngliOi Tranf. edit. i. pag. 2 16.
t Experiments and Obfervations, Vol. II. pag. 40, 2a. £d.
( J-to )
» V. Of the abjorftion of Nit reus Gas ly
Water.
Amongft the properties of nitrous gas noticed
by its great difcoverer, is that of abforbability
by water.
In expofing nitrous air to diitilled water. Dr.
Prieftley found a diminution of the volume of
gas, nearly equal to one tenth of the bulk of
the water ; and by boiling the water thus im-^
pregnated, he procured again a certain portion
of the nitrous gas.
Humbolt, in his paper on eudiometry, men-
tions the diminution of nitrous gas by water. This
diminution, he fuppofes to arife from the decom-
pofition of a portion of the nitrous gas^ by the
water, and the confcquent formation of nitrate
of ammoniac*
^ He lays, '' On a obferve, (depuis quon travaille fur le
^* purete de I'air) que le gaz nitreux, fecoue avec I'eau, en
•' foufFre une diminution de volume. Quelques phyficicns
" attribuent ce changeraent a une vraie abforption, a une
'* diflblution du gaz nitreux dans I'cau j d'autres a J'air con-
'' tenu dans les interftices de tous les fluides. Le cit.
*' Vanbreda, a Delft, a fait des recherches tres-exades fur
" I'influence des eaux de pluie et de puit, fur les nombres
•* eudiometriqucsj et les belles experiences du cit. Haflcn-
( 141 )
I confefs; that even before the following ex-
periments were made, 1 was but little inclined
to adopt this opinion : the fmall diminution
of nitrous gas by water, and the uniform limits
of this diminution, rendered it extremely im-
probable*
a. To afcertain the quantity of nitrous gas
'*■ fratz, fur Pabondance d'oxygene, contenue dans les caux
'^ de neige et de pluie, font fuppofer que I'air des interftices
" de Teau joue uu role irnportant dans Tabforption du gaz
*' nitreux. En comparant ces efFets avec les phenomenes
^' obferve dans la decompofition du fulfate de fer, nous fup-
*' posames, le cit. Taffaert et moi, que le limple contaft du
" gaz nitreux avec I'eau diftillee pourroit bien caufer une
*^ decompofition de ce dernier. Nous examinames foign-
" eufement une petite quantite d'eau dillillee, fecouee avec
*' beaucoup de gas nitreux trc;s-pur, et nous trouvames,
" au moyen de la terre calcaire, et I'acide m^iiatique, qu'il
*' s'y forme du nitrate (Tammoniaque. L'eau fe docompofe
*' en cette operation, par un double affinitc de I'oxygene
^' pour le gaz nitreux^ et de Thydrogene pour I'azote ; il fe
" forme de Tacide nitrique et de \ ammoniaqiic -, et, quoique
*' la quantite du dernier paroiffe trop petite pour en evaluer
" cxa6traent la quantite, fon exiftence cependant fe mani-
" fefte, (a ne pas fans douter) par le degagement des va-
" peurs, qui blanchiffent dans la proximite de I'acide mu-
*^ riatique. Voila un fait bicn frappant que la corapofitioii
" d'une fubftance alcaline par le conta6t d'une acide, et de
*•' I'cau.
Annales de Chlmie. t. xxviii. pag. 1.03.
( 14'2 )
abtorbable by pure water, and the limits of ab-
Ibrption^ I introduced into a glafs retort about
5 ounces of water, which bad been previoufly
boiled for fome hours. The neck of the retort
was inverted in mercury, and the water made
to boil. After a third of it had been diililled,
fo that no air could poffibly remain in the re-
tort, the remfiinder was driven over, and con-
denfed in an inverted jar filled with mercury.
To three cubic inches of this water,^ confined
in a cylinder graduated to ,o5 cubic inches, 5
cubic inches of nitrous gas, containing nearly one
thirtieth nitrogene, were introduced.
After agitation for near an hour, rather more
thrin ^-^ of ii cubic inch appeared to be abforbed;
but though the procefs was continued for near
two hours longer, no further diminution took
place.
The remaining gas was introduced into a
ttibe graduated to ,02 cubic inches. It mca-
fured " > hence -^ had been abforbed.
* Which was certainly as free from air as it ever can bc
obtaincd.
( 143 )
Confequently, 100 cubic inches of pure wa-
ter are capable of abforbing 1 1,8 of nitrous gas.
In the water thus impregnated with nitrous
gas I could diftinguifh no peculiar tafle ;* it
did not at all alter the color of blue cabbage
juice.
h. To determine if the abforption of nitrous
gas was owing to a decompofition of it by the
water, as Humbolt has fnppofed, or to a fimple
folution ; I procured fome nitrous gas from
nitrous acid and mercury, containing about
one feventieth nitrogene. ^5 cubic inches of
it, mingled with 25^ of oxygene, from ful-
phuric acid and manganefe left a refiduum of
^03. 5 cubic inches more were introduced
to 3 of water, procured in the lame manner as
in the laft experimeut, in the fame cylinder.
* Dr. Prieftley found diflilled v/atcr, faturated with
nitrous air, to acquire an aftringent tafte and pungent
imell. In fome unbailed impregnated pump water, I once
thought that I perceived a fubacid tads } but it was ex-
tremely flight, and probably owing to nitrous acid formed
by the union of the oxygene of the common air in the wa-
ter, with fome of the nitrous gas.
( 34«>
J^
ir» leatcd. faaB^riniei
vCEas te wcAy vtc
X^toAic
«atfer^tf0i^t0#
( 145 )
3, That at the temperature of 212% nitrous
gas is incapable of remaining in combination
with water.
Humbolt's opinion relating to the decompo-
fition of nitrous gas by water, is founded upon
the difengagement of vapor from diflilled water
impregnated with nitrous gas, by means of lime,
which became white in the proximity of the mu-
riatic acid. But this is a very imperfecS, and
fallacious ted, of the prefence of ammoniac. I
have this day, April 2, 1800, heated 4 cubic
inches of diftillcd water, impregnated with
nitrous gas, with caufliclime; the vapor cer-
tainly became a little whiter when held over a
vetfcl containing muriatic acid ; but the vapor
of diflilled water produced precifely the fame
appearance, =* which was owing, moil likely, to
* As carbonic acid and ammoniac arc both produ6ts of
aoimaliiation, is it not probable that our common waters
particularly thofe in, and near towns and cities, contain car-
bonate of ammoniac ? Iffo, this fait will always exift in
them after diflillation. In the experiments on carbonate of
ammoniac, to which I have often alluded, I found, in
diftilling a folution of this fait in water, that before half of
K
( 140 )
the combination of the acid with the aquooas
vapor. Indeed^ when I added a particle of
nitrate of ammoniac, which might have equalled
one twentieth of a grain, to the lime and im-
pregnated water, the increafed whitenefs of the
vapor was but barely perceptible, though this
quantity of nitrate of ammoniac is much more
confiderable than that which could have been
formed, even fuppofing the nitrous gas decom-
pofed.
VI. Of the ahforpion of Niirous Gas hy
Water of different kinds.
In agitating nitrous gas over fpring water,
the diminution rarely amounts to more than
one thirtieth, the volume of water being taken
as unity. I at firft fufpedted that this great dif-
thc water had pafled into the recipient, the carbonate
of ammoniac had fublimed j fo that the diftilled folulion
was much ftrcnge^: than before, whilftthe water remaining
in the retort was taftelefs. Will this fuppofition at all ex-
plain Humbolt's miftake ?
( 147 )
ference in the quantity of gas abforbedby fpring
water, and pure water, depended on carbonic
acid contained in the lad, diminifhing the at-
tradlion of it for nitrous gas : but by long boil-
ing a quantity of fpring water confined by mer-
cury, I obtained from it about one twentieth of
its bulk of air, which gave nearly the fame
diminution with nitrous gas, as atmofpheric
air.
This facSl induced me to refer the difference
ofdiminutioa to the decompofition of the at-
mofpheric air held in folution by the water,
the oxygene of which I fuppofed to be con-
verted into nitric acid, by the nitrous gas,
whilft the nitrogene was liberated ; and hence
the increafed refiduum.
a, I expofed to pure water, that is, water
procured by diftillation under mercury, nitrous
gas, containing a known quantity of nitrogene.
After the abforption was complete, I found the
fame quantity of nitrogene in the refiduum, as
was contained in a volume of gas equal to the
whole quantity employed.
( 148 )
h. Spring water boiled for fomc hours, and
fiifFered to cool under mercury, abforbeda quan-
tity of nitrous gas equal to one thirteenth of its
bulk ; which is not much lefs than that
abforbed by pure water.
c. I expofed to fpring water^ 10 meafures of
nitrous gas ; the compofition of which had
beeii accurately afcertained ; the diminution
was one twenty-eighth, the volume of water
being taken as unity. On placing the refiduum
in contadl with folution of fulphate of iron, the
nitrogene remaining w^as nearly one-twentieth
more than had been contained by the gas
before its expofure to water.
d. Diftilled water was faturated with com-
mon air, by being agitated for fome time in the
atmofphere. Nitrous gas placed in conta6l with
this water, underwent a diminution of - ;
the volume of water being unity. The gas re-
maining after the abforption contained about
one twenty - feventh nitrogene more than
before.
e. Nitrous gas expofed to water combined
( 149 )
with about one fourth of its volume of carbonic
acidj diminifhed to - * nearly. The remainder
contained little or no fuperabundant nitro-
gene.
From thefe obfervations it appears, that the
different degrees of diminution of nitrous gas
by different kinds of Nvater, may depend upon
various caufes.
1. Lefs nitrous gas will be abforbed by
water holding in folution earthy falts, than by
pure water ; and in this cafe the diminution of
the attraflion of water for pitrous gas will pro-
bably be in the ratio of the quantities of fait
combined with it. a. h.
2. The apparent diminution of nitrous
gas in water, holding in folution atmofphe-
ric air, will be lefs than in pure water,
though the abfolute diminution will be
greater ; for the fame portion will be abforbed,
whilft another portion is combined with the
oxygene of the atmofpheric air contained in the
water; and from the difengagement of the
" The water ftill bein^ unity.
( 150 )
nitrogene of this air, arifesian increafed refi-
duum. c, d.
3. Probably in waters containing nitrogene,
hydrogene, and other gafes, abforbable only to
a flight extent, the apparent diminution will be
lefs, on account of the difengagement of thofe
gafes from the water, by the (Irongcr affinity of
nitrous gas for that fluid.
4. In water containing carbonic acid, and
probably fome other acid gafes, the diniinution
will be fmall in proportion to the quantity of
gas contained in the water : the affinity of
this fluid for nitrous gas being diminifhed by its
greater affinity for the fubftance combined
with it. e,
ThedifFerent diminution of nitrous gas Vvhen
agitated in different kinds of water, has been
long obferved by experimenters on the conflitu-
ent parts of the atmofphere, and various folutions
have been given of the phaenomenon ; the mod
fingular is that of Hurabolt.^ He fuppofes
♦ He fays '^ 100 parties de gaz nitrcux, (a o.l4 d'azote) fe-
^* couees avec I'eau diftill^C; recemment cuite, diminuent en
»
( "51 )
that the apparent diminution of nitrous gas is
lefs in fpring water than diftilled water, on ac-
count of the decompofition of the carbonate of
lime contained in the fpring water, by the nitrous
acid formed from the contad of nitrous gas
with the water ; the carbonic acid difengaged
from this decompofition increafing the refi-
duum.
This opinion may be confuted without even
reference to my obfervations. It is, indeed, , #
" volume de 0.1 1, ou 0.12. Ce meme gaz, en contact avec
'' I'eau de puits, iie perd que 0.02. La caufe de cette dif-
*' ference de 0.9, ou 0.10, ne doit pas etre attribuee ni a
" rimpurite de I'air atmofpherique, contenu dans les inter-
'^ fiices de I'eau, ni a la decompolition de cette eau meme.
'^ Elle n'eft qu'apparente ; car I'acide nitrique, qui fe forme
"^ par le contat3: du gaz nitreux avec I'eau de puits, en do-
'^ compofe le carbonate de chaux. II fe degage de I'acidc
** carbonique, qui, en augmentant le volume du refiJu, rend
'' I'abforption du gaz nitreux moins fenfible. Pour deter-
^' miner la quantitc de cet acide carbonique, je lavai Ic
*' refidu avec de I'eau de chaux. Dans un grand nombre
** d'experiences, le volume diminna de O.OC), ou 0,07. II
'' faul en concluire que I'eau de puits abibrbe reellement
'' 9 -|- 2, ou 7 -[- 2 parties de gas nitreux, c'eft-a-dire, :\
" peu-pr^s la meme quantite que I'eau diltiJlee,"
Aunales deCbiri^ic, xxviii. pag. 151.
'j^^
( 152 )
altogether unworthy of a philofopher, generally
^ acute and ingenious. He feems to have for-
^ gotten that carbonic acid is abforbable by
water.
VII. Of the ahforpHon of Nitrous Gas, hy
folution of pale green Sulphate of Iron,
f a. The difcovery of the exadl difference be-
tween the fulphates of iron, is owing to Prouft.*
According to the ingenious refearches of this
chemift, there exifl two varieties of fulphate of
iron, the green and the red. The oxide in the
green fulphate contains — oxygene. This fait,
when pure, is infoluble in fpirit of wine ; its
folution in water is of a pale green color; it is
not altered by the gallic acid, and affords a
white precipitate with alkaline priiffiates.
The red fulphate of iron is foluble in alcohol
and lincryflalizable; its oxide contains — oxy-
gene. It forms a black precipitate with the
gallic acid, and with the alkaline pruHiates, a
blue one.
>^ Nicholfon's Phil. Jour. No. 1, p. 453.
s
( 153 )
The common fulphatesofiron generally con-
lift of combinations of thefe two varieties in
different proportions.
The green fulphate may be converted into 4
the red by oxygenated muriatic acid or nitric i
acid. The common lulphate may be converted
into green fulphate, by agitation in contadl
with fulpburated hydrogene.
The green fulphate has a ftrong afiinity for
oxygene, it attracts it from the atmofphere, from
oxygenated marine acid, and nitric acid. The
alkalies precipitate from it a pale green oxide,
which if expofed to the atmofphere, rapidly be-
comes yellow red.
The red fulphate of iron has no affinity
for oxygene, and when decompofed by the
alkalies, gives a red precipitate, which under-
goes no alteration when expofed to the atmof-
phere.*
b. The abforption of nitrous gas by a folution
of fulphate of iron, was long ago difcovered by
* I have been able to make thefe obfervations on tlie
fulphates of iron, moft of them after Prouft.
I
I
( 154 )
Prieftley. During this abforption, he remarketl
a change of color in the folution, analogous to
4^ that produced by the mixture of it with nitric
1 acid.
This chemical fa<S has been lately applied
by Humbolt, to the difcovery of the nitrogene
generally mingled with nitrous gas.
Vauquelin and Humbolt have publifhed
a memoir, on the cauics of the abforp-
tion* of nitrous gas by folution of fulphate
of iron. They faturated an ounce and half of
fulphate of iron in folution, with .180 cubic
inches of nitrous gas.
Thus impregnated it ftrongly reddened tinc-
ture of turnfoyle ; when mingled with fulphuric
acid, gave nitric acid vapor ; and faturated with
potafh, ammoniacal vapor.
By analyfis, it produced as much ammoniac
as that contained in 4 grains of ammoniacal
muriate, and a quantity of nitric acid equal to
that exitling in 17 grains of nitre. Hence they
'^•' Annales de chimie, vol. xxviii. pag. 182,
( 155 )
concluded, that the nitrous gas and a portion of
the Vvater of the folution, had mutually deconi-
pofed each other; the oxygene of the water com-
bining with the oxygene and a portion of the
nitrogene of nitrous gas to form nitric acid ;
and its hydrogene uniting with the remaining
nitrogene, to generate ammoniac.
They have taken no notice of the nature of
the fulphate of iron employed, which was mod
probably the common or mixed fulphate ; nor
of the attradllon of the oxide of iron in this fub-
fiance for oxygene.
c. Before I was acquainted with the obferv^ations
of Proud, the common fa6is relating to the
oxygenation of vitriol of iron induced me to
fuppofe, that the attradlion of this fubftancc for
oxygene was in fome way connedled with the
procefs of abforption. The comparifon of the
experiments of Humbolt and Vauquelin, with
the obfervations of Prouft, enabled me to dif-
cover the true nature of the procefs.
I procured a folution of red fulphate of
iron, by palling oxygenated muriatic acid
I
«>■
( 156 )
through a folution of common fulphate of iron,
till it gave only a red precipitate, when mingled
with cauftic potafh. To nitrous gas confined
by mercury, a fmall quantity of this folution
was introduced. On agitation, its color altered
to muddy green ; but the abforption that took
place was extremely trifling : in half an hour
it did not amount to ,2, the volume of the
folution being unity, w^hcn it had nearly re-
gained the yellow color.
I now obtained a folution of green ful-
phate of iron, by diflx)lving iron filings in diluted
fulphuric acid. The folution was agitated in
contact with fulphurated hydrogen e, and after-
wards boiled ; when it gave a white precipitate
with pruffiate of potaOi.
A fmall quantity of this folution agitated in
nitrous gas, quickly became of an olive brown,
and the gas was diminifhed with great rapidity;
in two minutes, a quantity equal to four times
the volume of the folution, had been abforbed.
Thefe fadls convinced me that the folubility
of nitrous gas in common fulphate of iron,
( 157 )
chiefly depended upon the pale green fiilphale
contained by it ; and that the attra6\ion of one
of the conftituents of this fubftance, the green
oxide of iron, for oxygene, was one of the
caufcs of the phaenonnenon.
d. Green fulphate of iron rapidly decompofes
nitric acid. li was confeqnently difficult to
conceive how any affinities exifting between ni-
trous gas, water, and green fulphate of iron,
could produce the nitric acid found in the ex-
periments of Vauquelin and Hunnbolt.
To afcertain if the prefencc of a great quan-
tity of water deilroyed the power of green ful-
phate of iron to decompofe nitric acid, I intro-
duced into a cubic inch of folution of green
fulphate of iron, two drops of concentrated
nitric acid.
The folution affiimed a very light olive color ;
pruffiate of potafh mingled with a little of it,
gave a dark green precipitate. Hence the
nitric acid had been evidently decompofed. As
no nitrous gas was given out, which is
always the cafe when nitric acid is poured on
( 158 )
cr}{lalired fulphate of iron, 1 fufpecSled that a
compleat decompofition of the acid had taken
place ; but when the folution was heated, a few
minute globules of gas were liberated, and it
gradually became flightly clouded.
Having often remarked that no precipitation
is ever produced during the converfion of green
fulphate of iron into red, by oxygenated muri-
atic acid, or concentrated nitric acid, I could
refer the cloudinefs to no other caufe than to
the formation of ammoniac.
To afcertain if this fubftance had been pro-
duced, a quantity of flacked cauftic lime was
thrown into the folution. On the application
of heat, the ammoniacal fmell was diftintSlly
perceptible, and the vapor held over orange
nitrous acid, gave denfe white fumes.
e. When I confidered this fadt of the decom-
pofition of nitric acid and water by the folution
of green fulphate of iron, and the change of
color effcdted in it by the abforption of nitrous
gas, exa611y analogous to that produced by the
decompofition of nitric acid; I was induced to
( 159 )
believe that the nitric acid found in the analjfis
ofVauquelin and Humbolt, had been formed
by the combination of feme of the nitrous gas
thrown into the folution with the oxygenc of
the atmofpherCc: and that the abforbability of
nitrous gas^ by folution of green fulphate of
iron,, was owing to a decompodtion produced
by the combination of its oxygenc with the
green oxide of iron, and of its nitrogcne with
the hydrogene difengaged irom w^ater, decom-
pounded at the fame time.
To afcertain this, I procured a quantity of
nitrous gas: it was fuitered to remain in con-
ta6l with water for ibme hours after its pro-
duflion. Transferred to the mercurial appa-
ratus, it gave no white vapor when placed
in contact with folution of ammoniac ; and con-
fequently held no nitric acid in folution.
Into a graduated jar filled with mercury, a
cubic inch of concentrated folution of pure
green fulphate of iron was introduced, and 7
cubic inches of nitrous gas admitted to it.
The folution immediatelv became dark olive at
nmtk
( 160)
the edges, and on agitation this color was dif-
fuTed through it. In 3 minutes, when near 5^
cubic nichets h:.d been abforbed, the diminution
ceafcd The folutioii w:is now of a bright olive
brown, and tranrparcnt at the edges. After it had
reded for a quarter of an hour, no farther ab-
forption was obferved ; the color was the
fame, and no precipitation could be perceived.
A little of it was thrown into a fmall glafs tube,
under the mercury, and examined in the at-
mofphere. Its tafte was rather more aftringent
than that of folution of green fulphate ; it
did not at all alter the color of red cabbage
juice. When a little of it was poured on the
mercury, it foon lofl: its color, its tafte became
acid, and it quickly reddened cabbage juice,
even rendered green by an alkali.
To the folution remaining in the mercurial
jar, a fmall quantity of pruffiate of potafh was
introduced, to afcertain if any red fulphate of
iron had been formed; but in (lead of the pro-
dudlion of either a blue, or a white precipitate,
the whole of the Iblution became opaque^ and
chocolate colored.
( Ifll >
Surprifed at this appearance, I was at firft
induced to fuppofe, that the ammoniac formed
by the ilitrogene of the nitrous gas and the
hydrogene of the water,, had been fufficient to
precipitate from the fulphuric acid, the red
oxide of iron produced, and that the color of
the mixture was owing to this precipitation.
To diflcjivc any uncombined oxide that might
ex ill in the folution, I added a very minute
quantity of diluted fulphuric acid ; but little
alteration of color was produced. Hence, evi-
dently, no red oxide had been formed.
This unexpedled refult obliged me to theorife
a fecond time, by fuppofing that nitrate of am-
moniac had been produced, which by combining
with the white prufRate of iron, generated a
new combination. But on mingling together
green fulphate of iron, pruiliate of potafli, and
nitrate of ammoniac in the atmofphere, the
mixture remained perfectly white.
To afcertain if any nitric acid exified, com-
bined with any of the bafes, in the impregnated
folution, I introduced into it an equal bulk
( i62 J
bf diluted fulphuric acid : it became rather
paler ; but no green or blue tinge was produced.
Thatthepruflic acid had not been decompofed,
was evident from the bright green produced,
when lefs than a grain of dilute nitric acid was
admitted into the folution.
/. From thefc experiments it was evident, that
no red fulphate of iron, or nitric acid, and confe-
quently no ammoniac, had been produced after
the abforption of nitrous gas by green fulphate
of iron. And when I compared them with the
obfervatibns of Prieftley, who had expelled by
heat a minute quantity of nitrous gas from an
impregnated folution of common fulphate of
iron, and who found common air phlogifticated
by flanding in contact with it, I began to fuf-
pe6l that nitrous gas was fimply diflblved in
the folution, without undergoing decompofi-
tion.
g. To determine more accurately the nature of
the procefs, I introduced into a mercurial
cylinder 410 grains of folution of green fulphate
of iron, occupying a fpace nearly equal to a
( 163 )
cubic incli ami quarter ; it was faturated with
nitrons gas, by abforbing 8 cubic inches. This
faturated folution exhibited the fame appearance
!is the lafi: ; and after remaining near an hour
untouched, had evidently depofited no oxide
of iron, nor gained any acid properties.
Into a fmall mattrafs filled with mercury,
naving a tight ll:opper with ' a curved tube
adapted to it, the greater part of this folution
was introduced ; judging from the capacity of
the mattrafs, about 50 grains of it might have
been loft. To prevent conrimon air from coming
in contadl with the folution, the ftopper was
introduced into the mattrafs under the mercury;
the curved tube conneded with a graduated
cylinder filled with that fubftance ; and the
mattrafs brought over the fide of the mercurial
trough. But in fpitc of thefe precautions a
large globule of common air got into the top of
the mattrafs, from the curvature of the tube.
When the heat of a fpirit lamp was applied to
the folution, it gave out gas with great rapidity^
and gradually loft its color. When 5 cubic
( 164 )
inches were collc61cd it became perfeeily pale
green, whilft a yellow reel precipitate was depo-
fited on the bottom of the mattrafs.
On pouring a little of the clear folution into
prnfiiatc of potafh, it gave only white prufliate
of iron.
But on introducing a particio of fulphuric
acid into the folution, fufficient to diffolve fome
of the red precipitate, and then pouring a
little of it into a folution of prufliate of potafh,
)t gave a fine blue prufliate of iron.
Hence the red precipitate was evidently red
yellow oxide of iron.
I now examined the gas, fufpeding that it
was nitrous oxide. On mingling a little of it
with atmofpheric air, it gave red vapor, and
diminifhed. Solution of fulphate of iron intro-
duced to the remainder, almoft wholly abforbed
it : the fmall reiidual globule of nitrogene could
not equal one thirtieth of a cubic inch.
Confequcntly it was nitrous gas, nearly pure.
Cauftic potafli was now introduced into the
folution, till all the oxide of iron was precipi-
tated. The folution, when heated, gave a
( 165 )
flrong fmell of ammoniac, and dcnfe white
fumes when held over muriatic acid. It was
kept at the heat of ebullition till the evapora-
tion had been nearly compleated. Sulphuric
acid poured upon the refiduum gave no yellow
fumes, or nitric acid vapor in any way per-
ceptible ; even when .heated and made to boil,
there was no indication of the production of
any vapor, except that of the fulphuric acid,
h. This experiment, compared with the others,
feemed almoft to prove, that nitrous gas
combined with folution of pale green fulphate
of iron, at the common temperature, without
decompofition ; and that when the impregnated
folution was heated, the greater portion of gas
was difengaged, whilQ the remainder was de-
compounded by the green oxide of iron ; which
attracted at the fame time oxygene from the
water and the nitrous gas ; whilft their other
conftituent principles, hydrogCLe and nitrogene,
entered into union as ammoniac.
Whilfi, however, I was reafoning upon this
fmgular chemical change, as affording pre-
- mi
( 166 )
Jutnpiive proofs in favor of the exertion of iim-
ple affinities by the coni^ituent parts of com-
pound fubftances, a doubt concerning the
decompofition of the nitrous gas occurred to
me. As near as I could guefs at the quantity
of nitrous gas contained by the impregnated
folution, at Icaft j^ of it muft have been expelled
undecompounded.
More than a' quarter of a cubic inch of com-
mon air had been prefent in the mattrafs : the
oxygene of this common air mufl have com-
bined with the nitrous gas, to form nitric acid.
Might not this nitric acid have been decom-
pofed, and furnifhed oxygene to the red oxide
of iron, and nitrogene to the fmall quantity of
ammoniac found in the folution, as in dP
i. I now introduced to a folution of green ful~
phate confined by mercury, nitrous gas, per-
fectly free from nitric acid. "When the folution
was faturatedj a portion of it was introduced
into a fmall mattrafs filled with dry mercury, in
the mercurial trough. The curved tube was
clofed by a fitiall cork at the top, and filled
( 167 )
with nitrous gas ; it was then adapted to th^
mattrafs, which was raifed from the trough, and
the folution thus efFedlually preferved from the
contadl of the atmofphere.
When the heat of a fpirit lamp was applied
to the mattrafs, it began to give out gas with
great rapidity. After fome time the folution
loll its dark color, and became turbid. When
the produdlion of nitrous gas had ceafed, it was
fufFered to cool. A copious red precipitate
had fallen down ; which, examined by the fame
tefts as in the lad experiment, proved to be
red oxide of iron.
The folution treated with lime, as before,
gave ammoniac ; but with fulphuric acid, not
the llighteft indications of nitric acid.
k. Having thus procured full evidence of the
decompofition of nitrous gas in the heated folu-
tion, in order to gain a more accurate ac-
quaintance with the affinities exerted, I endea-
voured to afcertain the quantity of nitrous gas ,
decompofed by a given folution, under known
ci^cumftances.
( i6s )
Into a cylinder of the capacity of 20 cubic
inches, inverted in mercury, 11 50 grains of
foiution of green fulphate of iron, of fpecific
gravity 1.4, were introduced. Nitrous gas was
admitted to it, and after feme time 21 cubic
inches were abforbed.
The impregnated foiution was thrown into a
mattrafs, in the fame rn^nner as in the laft ex-
periment, and the fame precautions taken to
preferve it from the contadl of atmofpheric air.
A quantity was loft during the procefs of tranf-
ferring, which, reafoning from the fpace occu-
pied in the mattrafs by the remaining portion,
as determined by experiment afterwards, muft
have amounted nearly to 240 grains.
The curved tube from the mattrais was now
made to communicate with the mercurial air-
holder. By the application of heat 12^5 cubic
inches of nitrous gas were colled^ed, after the
common temperature had been reftored to the
mattrafs ; which wasfufTcred to remain in com-
munication with the condudling tube.
The foiution was now pale grccnj that is, of its
( 169)
natural color, and a confiderable quantity of
red oxide of iron had been depofitcd.
Solid cauftic potafli was introduced into it,
till all the green oxide of iron had been precipi-
tated^ and till the folution rendered green, red
cabbage juice.
A tube was now accurately connefled with
the mattrafsj bent, and introduced into a frnall
quantity of diluted fulphuric acid. Nearly half
of the fluid in it was ilowly diftilled into the
fulphuric acid, by the heat of a fpirit lamp.
The impregnated acid evaporated at a heat
above 212®, and gave a fmall quantity of cryf-
talifed fait, which barely amounted to two grains
and quarter : it had every property of fulphatc
of ammoniac. Sulphuric acid in cxcefs was
poured on therefiduum, and the whole difiilled
by a heat not exceeding 300®, into a fmall quan-
tity of water. This water, after the proccf?,
tafted (Irongly of fulphuric acid; it had no
peculiar odor. Tin thrown into it when heated,
was not perceptibly oxydated ; mingled with
flrontitic lime W4lcr, it gave a copious white
( 170 )
precipitate, and after the precipitation became
almoft taftelefs. Hence it evidently contained
no nitric acid.
The 12,5 cubic inches of undecompounded
gas that came over were examined ; and ac-
counting for the fmall quantity of common air
previoufly contained in the airholder, muft have
been almoft pure.
/. Now fuppofing927 grains of the impregnated
folution (including the weight of the nitrous
gas), to have been operated upon, this muft
have contained about l6,7 cubic inches of ni-
J trousgas. But 12,5 cubic inches efcaped un>-
decompoundod : hence 4,2 were decompofed ;
and thefe weigh 1,44 grains, and are compofed
of ,8 oxygene, and ,64 nitrogene.*
Confequently, the nitrous gas muft have fur-
nifhed ,8 of oxygene to the green oxide of
iron.
But ,64 of nitrogene require ,15 of hydrogene
to form .79 of ammoniac t-f- confequently 1 of
^- Dlvifion IV. Seaion 5.
.• t Divifion II. Seaio|i l.
(in )
water was decompounded, and this furuiflied
^S5 of oxygene to the green oxide of Iron.
The green oxide of iron contains —^ oxygene ;
the red — . But the whole quantity of oxygene
fupplied from the water and nitrous gas is
8+ 85 = 1,65 ; and calcuhiting on the dif-
ference of the compofition of the red and green
pxide of iron, 5,7 grains of red oxide mud h.ave
been depofited, and confequently thefe would
faturate as much acid as ,79 grains of ammoniac,
or 4,1 grains of green oxide of iron.*
And fuppofing the ammoniac in fulphate of
ammoniac to be to the acid as 1 is to 3,^5^ 3.2
grains of fulphate of ammoniac mult have been
formed, containing about 2,4 grains acid ; and
then 6,5 grains of green fulphnte of iron mud
have been decompofed.
Hence we gain the following equation :
* No precipltntlon takes place during the couvf^rfion of
iblution of gieen fulphate into red j and tiie acid v^ppears
faturated.
t Divifion II, Seaion 6
'•^mmaamatm
( 172 )
6,5 green f. = 2,41 ful. acid + 4,1 gr.ox. iron.
1,44 nit. gas = ,64 nitrogene + ,8 oxygene.
1 water rzz ,85 oxygene -f- ,15 bydrogene.
equal
3,2 ful. am. = 2,41 f. acid + ,64 nit. +,15 hyd.
5,7 r. ox. iron = 4,1 gr. ox. iron + 1,6 oxyg.
Though the eftimation of the quantities in
this equation muft not be confidered as ftridlly
accurate, on account of the degree of uncer-
tainty that remains concerning the exadl nu-
merical expreffion of the quantities of the con-
ftituents of water, ammoniac, and the other
compound bodies employed ; yet as founded
on a fimple quantity, that is, the nitrous
gas decompofed, it cannot be very diftant
from the truth.
The fulphate of ammoniac given by experi-
ment, is confiderably lefs than that which was
really produced ; much of it was probably carried
off during the evaporation of the fuperabundant
acid.
( 173 )
The conclufions that may be drawn from this
experiment, afford a flriking inftanceofthe im-
portance of the application of the fcience of
quantity to the chemical changes : for the data
being one chemical fadi, the decompolition of
a given quantity of nitrous gas by known agents ;
the compofition of nitrous gas, of water, am-
moniac, the oxides of iron, and fulphate of
ammoniac ; we are able not only to determine
the quantities of the limple conftituents that
have entered into new arrangements, but like-
wife the compofition of two compound bodies,
the green and red fulphates of iron. '^
m. Though from the experiments in e it
appeared that no decompofition of nitrous gas
had been produced during or even after its
abforption by folution of fulphate of iron at
the common temperature ; yet a fufpicion
that it might take place flowly, and that
. * According to the eftimation in the equation, 6.5 of
dry green fulphate of iron contain 4.1 green oxide of iron,
and 2,4 of Kirwan's real fnlphuric acid : and 8.1 red ful-
phate of iron, contain 2 4 acid, and 5.7 red oxide of iron,
^L^^h^ -... — — - ■■ ^ ■ ^-^
( i74 )
indications of it might be given by depofi-
tion, induced me to examine minutely two
impregnated folutions, one of which had been
at reft, confined by mercury, for 19 hours, and
the other for 11 . ' In neither of them c>ould I
difcov^r any depoiition, or alteration of color,
which might denote a change.
Two cubic inches of oxygene were admitted
to half a cubic inch of one of thefe folutions.
The oxygene was flowly abforbed, and the folu-
tion gradually loft its color.
To afcertain if during the converfiun o{ the
nitrous gas held in folution by fulphate of
iron, into nitric acid, by the oxygene of the
atmofphere at the con)mon temperature, any
water was decompofed ; I fufFered an impreg-
nated folution, weighing nearly two ounces, to
remain in conta6l with the atmofphere at 57° —
62°, till it was become perfe<5ily pale. It then
had a ftrong acid tafte, cfFervefced with car-
bonate of potath, and gave a blue precipitate
with pruffiatc of potafh. — It was faturated
with quicklime, and heated ; flight indications
( i75 )
of the prefence of ammoniac were perceived.
As in this experiment the nitric acid had beeu
mod probably decompofed by the green oxide
of iron, as in/, I fent oxygenated muriatic acid
through an impregnated folution, till all the
green oxide of iron was converted into red, and
all. the nitrous gas into nitric acid.
This folution faturated with potafh, and heated,
gave no ammoniacal fmell.
From thefe experiments we may conclude,
ift. That folution of red fulphate of iron
has little or no affinity for nitrous gas^; and
that folution of common fulphate ablbrbs nitrous
gas only in proportion as it contains green
fulphate.
2dly. That folutions of green fulphate of
iron difTolvc nitrous gas in quantities propor-
tionable to their concentration, without effcclinrt-
* The muddy green color produced in a roliiiion cf red
fulphate of iron agitated in nitrons gas, depended npon
impurities in the mercury. I have iince found, that when
the folution is completely oxygenated, the diminution is
barely perceptible.
( 176 )
any decompofition of it at common temperatures.
And the foliibility o^ nitrous gas in folution
of green fulphate, may be fuppofcd to depend
on an equilibrium of affinity, produced by the
following fimple attra6lions :
1. That of green oxide of iron for the oxy-
gene of nitrous gas and water.
2. That of the hydrogene of the water
for the nitrogene of the nitrous gas.
3. That of the principles of the fulphu-
ric acid, for nitrogene and hydrogene.
3dly. That at high temperatures, that is,
from 200° to 300^^, the equilibrium of affinity
producing the bmary combination between
nitrous gas and folution of green fulphate of
iron is dcftroyed ; the attra6iion of the green
oxide of iron for oxygenebeingincreafed ; whilft
probably that of nitrogene for hydrogene is
diminifhed.
Hence the nitrous gas is either liberated,* in
* Perhaps the liberation of nitrous gas from the folution
( 177 )
cohreqaence of the affinity between oxygeind
and hydrogene, and oxygene and nitrogene not
following the fame ratio of alteration on in-
creafed temperature; or decompofed, becaufe
at a certain temperature the green oxide exerts
fuch affinities upon water and nitrous gas, as to
attra(fl oxygene from both of them to form red
oxide ; whilft the ftill exiftitig affinity between
the hydrogene of the one, and the nitrogene of
the other, difpofes them to combine to form
ammoniac.
4thly. That the change of color produced by
introducing nitric acid to folution of commonL
fulphate of iron, exactly analogous to that o'c-
cafioned in it by impregnation with nitrous gas,
is owing to the decompofition of the acid^ by
the combination of its oxygene with the greea
takes place at a lower temperature than its dccompolition.
I have always obferved that the quantity of yellow pre-;
cipitate is greater when the folution is rapidly made to
boil. Were it poliible to heat it to a certain tem-
perature at once, probably a compleat decompolitioii
would taUft place.
( 178 >
oxide of iron, and of its nitrous gas with the
folution.
5thly. That nitrous gas in combination with-
folution of green fulphate of iron, is capable of
exerting a ftrong affinity upon free or loofely
combined oxygene, and of uniting with it to
form nitric acid.
n. The produces obtained from a folution
of fulphate of iron faturated with nitrous gas,
by Vauquclin and Humbolt, and their confe-
quent miftake with regard to the nature of the
procefs of ablbrption,* muft have arifen from
expofure of their impregnated folution to the
atmofphere.
Indeed, from the acidity of it, on examina-
tion, from the fmall portion of ammoniac, and
the large quantity of nitric acid obtained, it
appears mod probable that the whole of the
nitrous gas employed was converted into nitric
acid, by combining with atmolplieric oxygene;
for no nitric acid could have been obtained in
* A-nnales de Chimic. T. 38, pag. IS;.
the mode in which they operated, unlefs the
green oxide of iron in the fblution had been
previoufly converted into red.
Vlir. On the dhforplon of Nitrous Gas by
folution of green Mzirtaie of Iron^
a. The analogy between the affinities of the
bonftititents of the muriate and fulphate of iron,
induced me to conjcdurc that they poffefled
fimilar powers oAabforbing nitrous gas ; and I
foon found that this was a(5tually the cafe ; for
on agitating half a cubic inch of folution of
muriated iron, procured by diflolving iron
fdings in muriatic acid, in nitrous gas, the gas
was abforbed with great rapidity, whilft the
folution aflumed a deep and bright browii
tinge.
h. Prduft,'''* who as I have before mentioned^,
fuppofes theexiftence of two oxides of iron only.
* Annales de Chimie, xxiii. pag. 85} or Nicholfoni
Phil. Journal vol. i, pag. 45,
^^
( 180)
one containing ^J-oxygene, the other ---, has
afTamed, that the muriatic acid, and inoit other
acids as well as the fulphnric^ are capable of
combining with thefe oxides, and of forming
ivith each of them a diftindl fait. He has,
however, detailed no experiments on the mu-
riates of iron.
As thefe falts are ftill more diftindl from each
other in their properties than the fulphates, arid
as thefe properties ai-e connedled with the
phsenomenon of the ablbfption and decompb-
fition of nitrous gas, I dial I detail the obfer-
vations I have been able to make upon them.
c. When iron filings have been diflblved iil
pure muriatic acid, and the folution prefcfved
from the contadl of air, it is of a pale greeii
color, and gives a white precipitate with alkaline
pruffiates. The alkalies throw down from it d
light green oxide of iron.
When evaporated, it gives cryftals almoft
white, which are extremely foluble in water ;
but infoluble in alcohol.
The folution of green muriate of iron has a
( 181 )
great affinity for oxygene, and attracts it from
the atmofphere, from nitric acid, and probably
from oxygenated muriatic acid.
When red oxide of iron is diffolved in muri-
atic acid, or when nitric acid is decompofed by
folution of green muriate of Iron ; the red
muriate of iron is produced. The folution of
this fait is of a deep brown red, its odor is pe-
culiar, and its tafte, even in a very diluted ilatCj
highly aftringent. It a6\s upon animal and
vegetable matters in a manner fomewhat analo-
gous to the oxygenated muriatic acid, rendering
them yellowidi white, or yellow.*
Sulphuric acid poured upon it, produces a
fmell refembling that of oxygenated muriatic
acid. Evaporated at a low temperature, it
gives an uncryftalifable dark orange colored
fait, which is foluble in alcohol, and when de-
compofed by the alkalies, gives a red precipitate.
With prufliate of potafli it gives prntTian blue.
* Probably by giving them oxygene ; whereas th(».
green muriate and fulphate blacken animal lubflances^ molj:
likely by abflrading from them OKygene.
( 182 )
The common muriate of iron confifts of dlf-:
ferent proportions of thcfe two falts. It may
be converted into red muriate by concentrated
nitric acid^ or into green by fulphur^ted hydro-
gene.
d. To afcertain if folutioq of red muriate
of iron was capable of abforbing nitrous gas, I
introduced intoa jar filled with mercury, a cubic
inch of nitrous gas, and admitted to it nearly
half a cubic inch of folution of red muriate of
iron. No difcoloration took place. By rnucb
agitation, however, an abforption of nearly ,2
was produced, and the folution became of a
muddy green. But this change of color, and
probably the abforption, was in confequence of
the oxydation of either the mercury, or fome
imperfedl metals combined with it, by the
oxygene of the red muriate. For I after-
wards found, that prccifely the fame change
of color was produced when a folution was
agitated over mercury.
e I introduced to a cubic inch of concen-
trated folution of green muriate of iron, 7 cubiq
( 183 )
incfies of nitrous gas, free from nitric acid ; the
folution indantly became colored at the edges,
and on agitation abforbed the gas with much
greate;* rapidity than even fulphate of iron ; in
a minute, only a q darter of a cqbic inch re-
inained.
The folution appeared of a very dark brown,
but evidently no precipitation had taken place
in it, and the edges, when viewed againft the
light, were tranfparent and puce colored^
Five cubic inches more gf nitrous gas were
now diffblved in the folution. The intenfity
of the color increafed, and after an hour no
depofition had takeft place. A little of it was
then examined in the atmofphere ; ft had a
much more afiringent tafte than the unimpreg-
nated folution, and effected no change in red
cabbage juice. When pru^ate of potafh was
introduced into it, its color changed to olive
brown. A few drops of the folution, that had
accidentally fallen on the mercury, foon became
cplorlefs, and then effervefced with carbonate
of potafh, and tailed ftrongly acid.
( 184 )
The remainder of the impregnated folution,
which muft have nearly equalled ,75 cubic
inches, was introduced into a mattrafs, having
a ftopper and curved tube, as in the experi-
ments on the folution of fulphate of iron; great
care being taken to preferve it from the contadl
of air.
The mattrats was heated by a fpiritlamp, the
curved tube being in communication with a
mercurial cylinder- Near 8 cubic inches of
nitrous gas 'were colledled, when the folution
became of a muddy yellow. It was fufFered to
cool, and examined. A fmall quantity of
yellow precipitate covered the bottom of the
mattrafs ; the fluid was pellucid, and light
green. A little of it thrown on prufliate of
potafh, gave a white precipitate, colored by
Hreaks of light blue. When the yellqw pre-
cipitate was partly diflblved by fulphuric acid,
a drop of the folution, mingled with prufliate of
potafh, gave a deep blue green.
Hence, evidently, the precipitate was red
oxide of iron.
( 185 )
Cauftic potafh in excefs was infroduced into
the remainder of thq folution, and it was heated.
It gave an evident fmell of ammoniac, and
denfe white fumes, when held over flrong phlo-
gifticated nitrous acid.
When half of it was evaporated, fulphuric
^cid in excefs was poured on the remainder ;
n)uriatic acid was liberated, not perceptibly
combined with any nitric acid.
f. In an experiment that I made to afcertaia
the quantity of nitrous gas capable of combining
with folution of green muriate of iron ; I found
that ^*]b cubic inches of fatnrated folution ab-
forbed about 18 of nitrous gas, which is nearly
double the quantity combinable with an equal
portion of the flrongeft folution of fulphate of
iron. A part of this impregnated folution,
heated flowly, gave out more gas in proportion
to the quantity it contained, than the lafi, and
confeqiiently produced lefs precipitate ; fo that
I am inclined to fup{X)fc it probable, that at a
certain temperature, all the diilblved nitrous
gas may be difpelled from a folution.
-M
( J86 )
From thefe experiments we may conclude,
1(1. That the folution of green muriate of
iron abforbs nitrous gas in confequence of nearly
the fame affinities as folution of green fulphatc
of iron ; its capability of abforbing larger quan-
tities depending moft probably on its greater
concentration (that is, on the greater folubility
pf the muriate of iron), and perhaps, in fome
ineafure, on a nevy combining affinity, that of
muriatic acid for oxygene.
!2dly. That at certain temperatures nitrous
gas is either liberated from folution of green
muriate^ or decompofed, by the combination
of its oxygene v;lth green oxide of iron, and of
its nitrogene with hydrogene, produced by
water decompounded by the oxide at the fame
time.
IX. Ahforption of Nilrous Gas hy SoJutio7t of
Niirate of Iron.
a. As well as two fulphates and two muriates
i m )
of iron, there exift two nitrates.* When cqn-
centrated nitric acid is made to a<Si upon iron,,
nitrous gas is difengaged with great rapidity,
and with great increafe of temperature : the
folution affumes a yellovvifh tinge, and as the
procefs goes on, a yellow red oxide is pre-
cipitated.
Nitrate of iron made in this way, gives d>
bright blue mingled with pruffiate of potafh,
and decompofed by the alkalies, a red precipi-
tate. Its folution has little or no affinity for
nitrous gas.
L When very dilute nitric acid, that is,
fuch as of fpecific gravity 1,1 6, is made to
pxydate iron, vyithout the affiftance of heat,
the folution gives out no gas for fome time, and
becomes dark olive brown : when neutralifed
it gives, decompofed by the alkalies, a light green
precipitate ; and mingled with pruffiate of pot-
afh, pale green pruffiate of iron.
* The cxiftence of green nitrate was not fufpcded by
mi^Om
( iss )
It owes its color to the nitrous gas it holds iii
fblution. By expofure to the atmofphere it
becomes pale, the nitrous gas combined with it
being converted into nitric acid.
It is then capable of abforbing nitrous gias,
and confifts of pale nitrate of irOn^ mingled with
red nitrate.
I have not yet obtained a nitrate of iron giving
only a white precipitate with pruffiate of pot-
afh, that is, fuch as contains only oxide of iron
at its minimum of oxydation ; for when pure
green oxide of iron is diflblved by very dilute
nitric acid, a fmall quantity of the acid is
generally decompofcd, which is likewife the cafe
in the decompofition of nitre by green fulphate
of iron. The folutions of nitrate of iron, bow-
ever, procured in both of thefe modes, abforb
nitrous gas with rapidity, and by fulphurated
hydrogenc might probably be converted into
pale nitrate.
As it is impoflible to obtain concentrated
folutions of pale nitrate of iron, chiefly
containing green oxide, its powers of abforbing
( 189 )
nitrous gas cannot be compared with the inn-
riatic and fulphitric folutions, unlefs they are
made of nearly the fame fpecific gravity.
Nitrous gas is difengagcd by heat from the im^^
pregnated folution of nitrate of iron, at the fame
time that much red oxide of iron is precipitated.
Whether any nitrous gas is decompofed^
I have not yet afcertained ; for vrhen un-
impregnated pale nitrate of iron is heated, a
part of the acid, and of the Vv^ater of the folu-
tion, is decompofed by the green oxide of iron ;'^
and in confequence ammoniac, and red nitrate
of iron formed, whilil red oxide is precipi-
tated.
X. Abforpion of Nitrous Gas hy other MetaU
lie Solutions,
a. White pruffiate of iron in conta61 with
vvater abforbs nitrous gas to a great extent, and
* In this proccfs nitrous oxide is fometimes given out;
as will be fcen hereafter.
becomes dark chocolate.*
h. Concentrated folution of fulphate of tiri^
^rohahly at its minimum of oxydation, abforbs
one eighth of itsbulk of nitrous gas, and becomes
brown, without depofition.
c. Solution of fulphate of zinc;}: abforbs about
one tenth of its volume of nitrous gas, and be-
comes green.
d. Solution of muriate of zinc:}; abforbs nearly
the fame quantity, and becomes orange brown.
e. Thefe are all the metallic fubftances on
which I have experimented. It is more thart
probable that there exifl; others pofTeiling iimilar
powers of abforbing nitrous gas.
Whenever the metals capable of decompofing
water exift in folutions at their minimum of
oxydation, the affinities exerted by them on
* Hence we learn why no nitrous gas Is difengaged when
Impregnated folution of fulphate of iron is decompofed by
prufliate of potafli, as in Div. IV. Sec. vii.
+ In both of thefe folutions the metal is at its minimum
of oxydation. The abforption of a fmall quantity of ni-
trous gas by wlnte vitriol was obferyed by Piicliley.
( m )
nitrous gas and water, will be ftich as fo pro-
duce combination. The powers of metallic
folutions to combine with nitrous gas at com-
mon temperatures, as well as to decompofe it
at higher temperatures, will probably be in the
ratio of the affinity of the metallic oxides they
contain, for oxygene.
XI. Tbe adlon of Sulphurated Hydrogene ori
folution of Green Sulphate of Iron, impregnated
with Nitrous Gas,
a. In an experiment on the abforption of
nitrous gas by folution of green fulphate o^ iron,
I introduced an unboiled folution of common
fulphate, deprived of red oxide of iron by ful-
phurated hydrogene, into a jar filled with ni-
trous gas ; the abforption took place as ufual.
and nearly (ix of gas entered into combinationy
the volume of the folution being unity. On
applying heat to a part of this impregnated
folution, the whole of the nitrous gas it con-
tained (as nearly as I could guefs), was expelled
( 192 )
undecompounded, and no yellow precipitate
produced. Prafliate of potafli poured into it
gave only white prufRate of iron ; and when it
was heated with lime, no ammoniacal fmell was
perceptible.
I could refer this phasnomenon to no other
caufe than to the exigence of a fmall quantity
ofAilphurated hydrogene in the folution. That
this was the real caufe I found from the follow-
ing experiment.
Ik One part of a folution of green fulpbate
of iron, formed by the agitation of commort
fulphate of iron in contadl with fulphuratcd
hydrogene, was boiled for fome minutes to
expel the fmall quantity of gas retained by it
imdecompoundcd. It had then no peculiar
fmell, and gave a white prufliate of iron With
prufliate of potafh ; the other part had a faint
odor of fulphurated hydrogene, and gave a
dirty white precipitate with prufliate of potafh.
Nearly equal quantities of each were faturated
with nitrous gas, and heated. The unboiled
impregnated folution gave out all its nitrous
( m )
gas undecompounded ; whilft in the boiled
folution it was partly decompofed, yellow pre-
cipitate and ammoniac being formed.
c. This fingular phaenortienon of the power of
a minute quantity of fulphurated hydrogene, in
preventing the decompoiition of nitrous gas and
water, by green oxide of iron, will mofl proba-
bly take place in other impregnated folutions.
It feems to depend on the ftrong affinity of the
hydrogene of fulphurated hydrogene for oxy-
gene.
XII. jidditional Ohfervations*
a. For feparating nitrous gas from gafes ab-
forbable to no great extent by water ; a well
boiled folution of green muriate of iron Ihould
be employed. Nitrous gas agitated in this is
rapidly abforbed, and it has no affinity for^ or
adlion on, nitrogene, hydrogene, or hydro-
carbonate.
h. Nitrous gas carefully obtained from mer-
cury and nitric acid, when received under mer-
N
( 104 )
Gury, or boiled water, and abforbed by folution
of green muriate, or fulphate of iron, rarely
leaves a refiduum of — of its volume : pre-
ferved over common water, and abforbed, the
remainder is generally from j^ to ^, from the
nitrogene difengaged by the decompofition of
the common air contained in the water.
c. The nitrous gas carefully obtained from
the decompofition of nitric acid of ] .26, by
copper, I have hardly ever found to contain
more than from ^ to ~ nitrogene, when received
through common water : when boiled water is
employed, the refiduum is nearly the fame as
that of nitrous gas obtained from mercury,
d, Confequently the gas from thofc two
folutions may be ufed in common. It is more
than probable, that the fmall quantities of
nitrogene generally mingled with nitrous gas
from copper and mercury, arife either fit)m the
common air of the vefTels in which it was pro-
duced, or that of the water over which it was
received. There is no reafon for fuppofing that
it is generated by a complete decompofition of
}
( m )
a portion of the acid.*
e. Whenever nitrous oxide is mingled with
nitrous gas and nitrogene, it muft be feparated
by well boiled water ; and after the correflions
are made for the quantity of air difengaged
from the water, the nitrous gas abforbed by the
muriatic folution*
•* Humbolt, who is the firft philofopher that has applied
the folution of fulphate of iron to afcertain the purity of
nitrous gas, aflerts that he uniformly found nitrous
gas obtained from folution of copper in nitrous acid, to
contain from fix tenths to one tenth nitrogene.
Annales de Chimie, vol. xxviii. pag. 14/.
DlVISIOI^f V.
EXPERTMENTS and 6BSERVAT10NS on the
produdiion of NITROUS OXIDE from NITROUS
GAS and NITRIC ACID, in different modes.
I. Preliminaries,
a. X he opinions of Prieftley* and Kirwan,t
relating to the caufes of the converfion of nitrous
gas into nitrous oxide, were founded on the
theory of phlogifton. The firft of thefe philo-
fophers obtained nitrous oxide by placing nitrous
gas in conta6l with moiftened iron filings, or
the alkaline fulphures. The lad by expofing it
to fulphurated hydrogene.
The Dutch chemifts, :}: the lateft experi-
* Vol. ii. pag. 5b, f P^i^- Tranf. vol. Ixxvi. pag. 133.
t Journal de Phyfique, torn, xliii, 323.
( 197 )
mentalifts on nitrous oxide, have fuppofed that
the produ(5iion of this fubftance depends upon
the fimple abftradlion of a portion of the oxy-
gene of nitrous gas. They obtained nitrous
oxide by expofing nitrous gas to muriate of
tin, to copper in folution of ammoniac, and
like wife by paiEng it over heated fulphur.
The diminution of volume fuftained by
nitrous gas during its converfion into nitrous
oxide, has never been accurately afcertained ;
it has generally been fuppofed to be from two
thirds to eight tenths.
h. Nitrous gas may be converted into nitrous
oxide in two modes.
Firft, by the fiipple abftradlion of a portion
of its oxygene, by bodies pofleffing a ftrong
affinity for that principle, fuch as alkaline
fulphites, muriate of tin, and dry fulphures.
Second, by the combination of a body
with a portion both of its oxygene and
nitrogene, fuch as hydrogene, when either in a
nafcent form, or a peculiar ftate of combir
nation.
( m )
c. Each of thefe modes will be diftindlly
treated of; and to prevent unneceflary repe-
titions, I fhall give an account of the general
manner in which the following experiments on
the converfion of nitrous gas into nitrous oxide,
have been conduced.
Nitrous gas, the purity of which has been
accurately afcertained by folution of muriate of
iron, is introduced into a graduated jar filled with
dry mercury. If a fluid fubftance is defigned
for the converfion of the gas into nitrous oxide,
it is heated, to expel any loofely combined air
which might be liberated during the procefs ;
and then carefully introduced into the jar, by
means of a fmall phial. After the procefs is
finifhed, and the diminution accurately noted,
the nitrous oxide formed is abforbed by pure
water. If any nitrous gas remains, it is con-
denfed by folution of muriate of iron ; other
refidual gafes are examined by the common
lefts. The quantity of nitrous oxide diflblved
by the fluid is determined by a comparative
experiment ; and the corrcflions for tempera-
( 199 )
ture and preflure being guefled at, the con-
clufions drawn.
If a folid fubftance is ufed, rather niore nitrous
gas than that defigned for the converfion, is
introduced into the jar. The fubftance is
brought in contadl with the gas, by being
carried under the mercury ; and as a little com-
mon air generally adheres to it, a fmall portion
of the nitrous gas is transferred into a graduated
tube, after the infertion, and its purity afcer-
tained. In other refpedts the procefs is con-
duiSed as mentioned above.
II. Of the converfion of Nitrous gas into JVi-
trous Oxide ^ hy Alkaline Sulj^hites,
The alkaline fulphites, particularly the ful-
phite of potafh, convert nitrous gas into nitrous
oxide, with much greater rapidity than any
other bodies.
At temperature 46^ l6 cubic inches, of
nitrous gas were converted, in lefs than an
hour, into 7,8 of nitrous oxide, by about 100
( '200 )
grains of pulverifed fulphite of potafli, contain*-
ing its water of cryftalifation. No fenfible in-
creale of temperature was produced during the
procefs, no water was decompofed, and the
quantity of nitrogene remaining aftpr the ex-
periment, was exadlly equal to that previoufly
contained in the nitrous gas.
The nitrous oxide produced from nitrous gas
by fulphite of potafh, has all the properties of
that generated from the decompofition of ni«
trate of ammoniac. It gives, as will be feen
hereafter, the fame produdls by analyfis. Phof-
phorus, the taper, fulphur, and charcoal, burn
in it with vivid light. It is abforbable by water,
and capable of expulfion from it unaltered, by
heat.
Nitrous gas is converted into nitrous oxide
by the alkaline fulphites with the fame readinefs,
whether expofed to the light, or deprived of its
influence.
The folid fulphites a6l upon nitrous gas much
more readily than their concentrated folutions;
they fliould however always be fuffered to
( 201 )
retain their water of cryilalifation, or otherwife
they attradl moifture from the gas, and render
it drier, and in confequence more condenfed
than it would otherwife be. In cafe per-
fe611y dry fulphites are employed, the gas
fhould be always faturated with moifture after
the experiment, by introducing into the cylin-
der a drop of water.
The fulphites, after expofure to nitrous gas,
are either found wholly, or partially, converted
into fulphates. Confequently the converfion of
nitrous gas into nitrous oxide by thefe bodies,
limply depends on the abftradlion of a portion
of its oxygene ; the nitrogene and remaining
oxygene afluming a more condenfed ilate of
exiftence.
If we reafon from the different fpecific gra-
vities of nitrous oxide and nitrous gas, as com-
pared with the diminution of volume of nitrous
gas, during its converfion into nitrous oxide,
100 parts of nitrous gas, fuppcfing the former
eftimation of the compofition of nitrous oxide
given in Divifion III, accurate, would confift
( 202 )
of 54 oxygene, and 46 nitrogene ; which is not
far from the true eftimation. Or afTuming the
compofition of nitrous gas, as given in Divifion
IV, it would appear from the diminution, that
100 parts of nitrous oxide confifted of 38 oxjr
gene, and 62 nitrogene,
III. Coyrcerfion of NitroKS Gas into Nitrous
Oxidey by Muriate of Tin, and dry Sulphur es.
a. Nitrous gas expofed to dry muriate of
tin, is flowly converted into nitrous oxide :
during this procefs the apparent diminution is
to about one half; but if the produ6ls are nicely
examined, and the neceflary corredions made,
the real diminution of nitrous gas by muriate of
tin, will be the fame as by the fulphites ; that
is, 100 parts of it will be converted into 48 of
nitrous oxide.
During this converfion, no water is decom-
poled, and no nitrogene evolved. Solution of
muriate of tin converts nitrous gas into nitrous
oxide ; but with much lefs rapidity than the
folid fait.
( 203 )
h. Nitrons gas expofed to dry and perfedlly
well made fulphures, particularly fuch as arc
produced from cryftalifed alumn* and charcoal
not fufficiently inflammable to burn in the
atmofphere, is converted into nitrous oxide by
the fimple abftradion of a portion of its oxygene,
and confequently undergoes a diminution
It is probable, that all the bodies having
ftrong affinity for oxygene will, at certain
temperatures, convert nitrous gas into nitrous
oxide. Prieftley, and the Dutch chemifts,
effe^ed the change by heated lulphur. Per-
haps nitrous gas fent through a tube heated,
but not ignited, with phofphorus, would be
converted into nitrous oxide.
IV. Decompofit'ion of Nitrous Gas, by Sid-
pburafed Hydrogenc.
a. When nitrous gas and fulphurated hy-
* That is, aliirnn containing fulphate of potidi.
( 204 )
drogene are mingled together, a decompoiition
of tbem flowly takes place. The gafes are
diminiflied, fulphur depofited, nitrous oxide
formed, and figns of the produ6lion of ammo-
niac* and water perceived.
In this procels no fulphuric, or fulphureous
acid is produced ; confequently none of the
fulphur is oxydated, and of courfe the changes
depend upon the combination of the hydrogene
of the fulphurated hydrogene, with different
portions of the oxygene and nitrogene of the
nitrous gas, to form water and ammoniac, the
remaining oxygene and nitrogene afTuming the
form of nitrous oxide.
This iingular exertion of attradlions by a
fimple body, appears highly improbable a priori,
nor did I admit it, till the formation of ammo-
niac, and the non -oxygenation of the fulphur,
were made evident by many experiments.
In thofe experiments, the diminution of the
nitrous gas was not uniformly the fame. It
* The produ6lion of ammoniac in this proccfs was ob^
ferved by Kirwan aud Auftin.
( 205 )
Varied from ^^ to ^. In the moft accurate of
them, 5 cubic inches of nitrous gas were con-
verted into 2.2 of nitrous oxide. Confequently
the quantity of ammoniac formed was ,04/
grains.
In experiments on the converfion of nitrous
gas into nitrous oxide, by fulphurated hydro-
gene, the gafes fhould be rendered as dry as
poffible. The prefence of water confiderably
retards the decompofition.
b. The fulphurcs* diflblved in water convert
nitrous gas into nitrous oxide. This decom-
pofition is not; however, produced by the iimplc
abftradlion of oxygene from the nitrous gas to
form fulphuric acid. It depends as well on the de-
•* Solution of fulphure of ftrontian, or barytes, iliould
be ufed. During the converlion of nitrous gas into nitrous
oxide by thofe bodies, a thin film is depoiited on the furface
of the folution. This film examined, is found to con lilt
of fulphur and fulphate. Poffibly the nitrous gas is wholly
decompofed by thehydrogene of the fulphurated hydrogene
in the folution, whilft the fulphate is produced from water
decompounded by the fulphur to form more gas for tho
faturation of the hydro-fulphure.
( 206 )
compofition of the fulphurated hydrogene dif-
folved in the folution^ or liberated from it. In this
procefs fulphur is depofited on the furface of the
fluid, fulphuric acid is formed, and the diminu-
tion, making the neceflary corredlions, is nearly
the fame as when free fulphurated hydrogene
is employed.
It is extremely probable that fulphurated hy-
drogene, in combination with the alkalies, as
well as with water, is capable of being flowly
decompofed by nitrous gas.
V. Decompoption of Nitrous Gas hy Nafcenf
Hydrogene.
a. When nitrous gas, is expofed to wetted
iron filings, a diminution of its volume flowly
takes place ; and after a certain time, it is found
converted into nitrous oxide.
In this procefs ammoniac* is formed, and the
iron partially oxydated.
* As was firft obferved by Piieftley and Auftiii, and as I
have proved by many experiments.
( 207 )
The water in contadl with the iron is decom-
pofed by the combination of its oxygene with
that fubftance, and of its hydrogene with a por-
tion of the oxygene and nitrogene of the nitrous
gas, to form water and ammoniac.
That the iron is not oxydated at the expencc
of the oxygene of the nitrous gas, appears very
probable from the analogy between this procefs,
and the mutual decompofition of nitrous gas
and fulphurated hydrogene. Befides, dry iron
filings effedl no change whatever in nitrous
gas, at common temperatures.
I have generally found about 12 of nitrous
gas converted into 5 of nitrous oxide in this
procefs ; which is not very different from the
diminution by fulphurated hydrogene. It takes
place equally well in light and darknefs ; but
more rapidly in warm weather than in cold.
h. Nitrous gas expofed to a large furface of
zinc, in contact with water, is flowly converted
into nitrous oxide ; at the fame time that am--
moniac is generated, and white oxide of zinc
formed. This procefs appears to depend, like
^a.^^
( 10^ )
the laftj upon the decompolition of water by
the affinities of part of the oxygene and nitre-
gene of nitrous gas, for its hydrogene, to form
ammoniac and water; and by that of zinc for
its oxygene. Zinc placed in contaft with
water, and confined by mercury,* decompofes
it at the common temperature. Zinc, when
perfectly dry, does not in the flighteft degree
a6l upon nitrous gas.
I have not been able to determine exadlly
the diminution of volume of nitrous gas, during
its converdon into nitrous oxide by zinc. In
one experiment 20 meafures of nitrous gas, con-
taining about ,03 nitrogene, were diminithed to
g, after an expofure of eight days to wetted
zinc ; but from an accident, I was not able to
afcertain the exa6l quantity of nitrous oxide
formed.
c. It is probable that moft of the imperfedl
metals will be found capable of oxydation, by
the decompofltion of water, when its hydrogene
is abftradled by the oxygene and nitrogene of
* As I have found by experiment.
( 209 )
nitrous gas. I have this day (April 14, J 800),
examined two portions of nitrous gas, one of
which had been expofed to copper filings, and
the other to powder of tin, for twenty-three
days.
The gas that had been expofed to copper was
diminifhed nearly two fifths. The taper burnt
in it with an enlarged flame, blue at the edges.
Hence it evidently contained nitrous oxide.
The nitrous gas in contadl: with tin had
undergone a diminution of one fourth only,
and did not fupport flame.
VI. Mifcellaneous Ohfervations on the converjion
of Nitrous Gas into Nitrous Oxide,
a. Dr. Priefl:ley found nitrous gas expofed to a
mixture of iron filings and fulphur, with water,
converted after a certain time, into nitrous
oxide. Sulphurated hydrogene is always pro-
duced during the combination of iron and ful-
phur, when they are in contadt with water ;
and by the hydrogene of this in the nafcent
o
( ^10)
ftate, fhe nitrous gas is moft probably decom-
pofed.
h. Green oxide of iron moiftened vvith water,
expofed to nitrous gas, flowly gains an orange
tinge, whilfl the gas is diminifhed. Moft
likely it is converted into nitrous oxide ; but
this I have not afcertained.
c I expofed nitrous gas, to the following bodies
over mercury for many days, without any
diminution, or apparent change in its properties.
Alcohol, faccharine matter, hydro-carbonate,
fulphureous acid, and phofphorus.
d, Cryftalifed fulphate, and muriate of iron,
abforb a fmall quantity of nitrous gas, and
become dark colored on the outfide ; but after
this abforption, (which probably depends on
their water of cryftalifation,) has taketl place,
no change is efFedled in the gas remaining,
e The power of iron to decompofe water being
much increafed by increafe of temperature, ni-
trous gas is converted into nitrous oxide much
more rapidly when placed in contaft with a fur-
face of heated iron, than when expofed to it at
(211)
common temperatures. During the decompo-
lition of nitrous gas in this way, ammoniac ^
is formed.
/. The curious experiments of Rouppe,"f*
on the abforption of gafes by charcoal, com-
pared with the phaenomena noticed in this
Divifion, render it probable that hydrogene in
a Hate of loofe combination with charcoal, will
be found to convert nitrous gas into nitrous
oxide.
VII. Recapitulation of conclujions concerning
the converfion of Nitrous Gas into Nitrous Oxide.
a. Certain bodies having a ftrong affinity
for oxygene, as the fulphites, dry fulphures,
muriate of tin, &c. convert nitrous gas into
nitrous oxide, by (imply attradling a portion of
its oxygene ; whilft the remaining oxygene
* As was obferved by Milner. Nitrous gas pafled over
heated zinc, or tin, I doubt not will be found converted
into nitrous oxide.
t Annates de Chimie. xxxii. p. 3.
:^E.M^J
( 212 ) ^
enters into combination with the nitrogene, and'
they afTume a more condenfed flate of exig-
ence.
h. Nitrous gas is converted into nitrous
oxide by hydrogene, in a peculiar ftate of ex-
iftence, as in fulphurated hydrogene ; and that
by a feries of very complex affinities. Both
oxygene and nitrogene are attradled from the
nitrous gas by the hydrogene, in fuch propor-
tions as to form water and ammoniac, whilft
the remaining oxygene and nitrogene * aflume
the form of nitrous oxide.
c. Nitrous gas placed in contacSl with bodies,
fuch as iron and zinc decompofing water, is
converted into nitrous oxide, at the fame time
that ammoniac is formed. It is difficult to
afcertain the exad rationale of this procefs. For
either the nafccnt hydrogene produced by the
decompofition of the water by the metallic fub-
flance may combine with portions of both the
'^ The decompoiition and recompolition of water, in this
procefs, ate analogous to fome of the phaenomena obferved
by the i^igcnioa* Mrs. Fulhame.
( 213 )
Qxygene and nitrogene of the nitrous gas ; and
thus by forming water and ammoniac, convert
it into nitrous oxide. Or the metallic fubftance
may attradl at the fame time oxygene from the
water and nitrous gas, whilft the nafcent hydro-
gene of the water feizes upon a portion of the
nitrogene of the nitrous gas to form ammo-
niac.
The degree of diminution, and the analogy
between this procefs and the decompofition of
nitrous gas by fulphurated hydrogene, render
the firft opinion mofi: probable.
VIII. The froduBion of Nitrous Oxide during
the oxydation of Tin, Zinc, and Iron^ in Nitric
Acid,
a. Dr. Prieftley difcovered, that during the fo-
lution of tin, zinc, and iron, in nitric acid, cer-
tain portions of nitrous oxide were produced,
mingled with quantities of nitrous gas, and
nitrogene, varying in proportion as the acid
employed was more or lefs concentrated.
( ai4 )
It has long been known that ammoniac is
formed during the folution of tin, zinc, and
iron, in diluted nitric acid. Confequently, in
thefe proceiTes water is decompofed.
I had defigned to inveftigate minutely thefe
phaenomena, fo as to afcertain the quantities
of water and acid decompounded, and of the
new produdls generated. But after going
through fome experiments on the oxydation of
tin without gaining conclufive refults, the labor,
and facrifice of time they demanded, obliged
me to defift from purfuing the fubjedl, till I
had completed more important inveftigations.
I {ball detail the few obfervations which have
occurred to me, relating to the produdion of
nitrous oxide from metallic folutions.
h. When tin is diflblved in concentrated
nitric acid, fuch as of 1.4, nitrous oxide is pro-
duced, mingled with generally more than twice
its bulk of nitrous gas. In this procefs but little
free nitrogenc is evolved, and the tin is chiefly
precipitated in the form of a white powder. If
the folution, after the generation of thefe pro-
( ^15 )
du<3s, is faturated with lime, and heated, the
ammoniacal fmeli is diftindl.
When nitric acid of fpecific gravity 1.24, is
made to ail upon tin ; in the beginning
of the procefs, nearly equal parts of nitrous gas
and nitrous oxide are produced ; as it advances,
the proportion of nitrous oxide to the nitrous
gas increafes : the largefl: quantity of nitrous
oxide that I have found in the gas procured
from tin is ^, the remainder being nitrous gas
and nitrogene.
When tin is oxydated in an acid of lefs fpe-
cific gravity than I.09, the quantities of gas
difen gaged are very fmall, and confift of nitro-
gene, mingled with minute portions of nitrous
oxide, and nitrous gas.
Whenever I have faturated folutions of tin
in nitric acid of different fpecific gravities, with
lime, and afterwards heated them, the ammo-
niacal fmell has been uniformly perceptible,
and generally mofl diflinfl when diluted acids
have been employed.
c. When zinc is difTolved in nitric acid,
(216)
whatever is its fpecific gravity, certain quanti^
ties of nitrous oxide are produced.
Nitric acids of greater fpecific gravity than
1.2, adl upon zinc with great rapidity, and
great increafe of temperature. The gafes dif-
engaged from thefe folutions conlift of nitrous
gas, nitrous oxide, and nitrogene ; the nitrous
oxide rarely equals one third of the whole.
When nitric acid of 1,104 is made to diflblve
zinc, the gas obtained in the middle of the pro-
cefs confifts chiefly of nitrous oxide. From
fuch a folution I obtained gas which gave a
refiduum of one fixth only when abforbed by
water. The taper burnt in it with a brilliant
flame, and fulphur with a vivid rofe-colored
light.
100 grains of granulated zinc, during
their folution in 300 grains of nitric acid, of
1,43, diluted with 14 times its weight of water,
produced 26 cubic inches of gas. Of this
gas gg were nitrous, - nitrous oxide, and the
remainder nitrogene. The folution faturated
with lime and beated, gave a diftind fmell of
ammoniac, '
( ^17 )
d. During the folution of Iron in concen-
trated nitric acid, the gas given out is chiefly
nitrous; it is however generally mingled vi/ith
minute quantities of nitrous oxide. When
very dilute nitric acids are made to adl upon
iron, by the affiftance of heat, . nitrous oxide is
produced in confiderable quantities, mingled
with nitrous gas and nitrogene ; the proportions
of which are fmaller as the procefs advances.*
The fluid remaining after the oxydation and
folution of iron in nitric acid, always contains
ammoniac.
e. As during the folution of tin, zinc, and iron,
in nitric acid, the quantity of acid is diminifhed
in proportion as the procefs advances, it is rea-
fonable to fuppofe that the relative quantities of
the gafes evolved are perpetually varying. In
the beginning of a diflblution, the nitrous gas
* From one of Dr. Prleftley's experiments, it appears
that hydrogene gas is fometimes difengaged during the
folution of iron in very dilute nitric acid bv heat. Tljis
phsenomenon has never occurred to mc.
( 218 )
generally predominates, in the middle nitrous
oxide, and at the end nitrogene.
f. During the generation of nitrous gas,
nitrous oxide, and ammoniac, from the decom-
pofition of folution of nitric acid in water, by
tin, zinc, and iron, very complex attractions
muft exift between the conftituents of the fub-
ftances employed. The acid and the water are
decompofed at the fame time, and in propor-
tions different as the folution is more con-
centrated, by the combination of thqir oxygenc
with the metallic body.
The nitrous gas is produced by the combina-
tion of the metal with -^ of the oxygcne of the
acid. The nitrous oxide is moft probably
generated by the decompofition of a portion of
the nitrous gas difengaged, by the nafcent hy-
drogene of the water decompounded; fome of
it may be poffibly formed from a more com-
plete decompofition of the acid.
The produdlion of ammoniac may arife,
probably from two caufes ; from the de-
compofition of the nitrous gas by the combi-
( ^19 )
nation of the nafcent hydrogen e of the water,
with portions of its oxygene and nitrogene at
the fame time ; and from the union of hy-
drogene with nafcent nitrogene liberated in
confequence of a complete decompofition of
part of the acid.
IX. Additional Ohfervations on the pro-
du6lion of Nitrous Oxide.
a. When nitric acid is combined with mu-
riatic acid, or fulphuric acid,* the quantities of
nitrous oxide produced from its decompofition
by tin, zinc, and iron, are rather increafed than
<limini(hed. The nitrous oxide obtained from
thefe folutions is, however, never fufficiently
pure for phyliological experiments. It is always
mingled with either nitrous gas, nitrogene, or
hydrogene, and fometimes with all of them.
i. From the folutions of bifmuth, nickel.
* As was difcovered by PrieftleV; and the Dutch Che-
mifts.
( 220 )
lead, and copper, in diluted nitric acid, I have
never obtained any perceptible quantity of
nitrous oxide : the gas produced is nitrous,
mingled with different portions of nitrogene.
Antimony and mercury, during their folution
in aqua regia, give out only nitrous gas.
Probably none of the metallic bodies, except
thofe that decompofe water at temperatures
below ignition, will generate nitrous oxide from
nitric acid. On cobalt and manganefe I have
never had an opportunity of experimenting :
manganefe will probably produce nitrous oxide.
c. During the folution of vegetable matters*
in nitric acid, by heat, very minute portions of
nitrous oxide are fometimes produced, always
however mingled with large quantities of nitrous
gas, and carbonic acid.
When nitric acid is decompounded by
ether, fixed oils, volatile oils, or alcohol,
towards the end of the procefs fmall quan-
tities of nitrous oxide are produced, and
* Such as the leaves, bark, and wood, of trees.
( 2^1 )
fometimes fufficiently pure to fupport the
flame of the taper.-j-
d. When green oxide of iron is diflblvcd in
nitric acid, nitrous oxide is produced, mingled
with nitrogene and nitrous gas.
e During the con verlion of green fulphate, or
green muriate of iron into red, by the decom-
pofition of dilute nitric acid, nitrous oxide. is
formed, mingled with different proportions
of nitrous gas and nitrogene.
/. When folution of green nitrate of iron is
heated, a part of the acid is decompofed, red
oxide is precipitated, red nitrate formed^ and
impure nitrous oxide evolved.
g. When iron is introduced into a folution of
nitrate of copper, the copper is precipitated in
its metallic ftate, whilft nitrous oxide, mingled
with fmall portions of nitrogene, is produced. =^
' Both zinc and tin precipitate copper in its
metallic form from folution in the nitric acid.
f As I have obferved after Prieftley.
* As was difcovered by Prieftley.
( 222 )
During thefe precipitations, certain quantities
of nitrous oxide are generated, mingled how-
ever with larger quantities of nitrogene than
that produced from decompofition by iron.
In all thefe procefTes ammoniac is formed, and
water confequently decompofed.
The decompofition of water and nitric acid,
during the precipitation of copper from folution
of nitrate of copper, by tin, zinc, and iron,
depends upon the ftrong affinity of thofe metals
for oxygene, and their powers of combining
with a larger quantity of it than copper.
X. Decompofition of Aqua Regia by Platina^
and evolution of a Gas analogous to Oxygenated
Muriatic Acid, and Nitrogene,
a, De la Metherie, in his effay on different
airs, has afTerted that the gas produced by the
folution of platina in nitro-muriatic acid, is
identical with the dephlogifticated nitrous gas
of Prieftley. He calls it nitrous gas with excefs
( 223 )
of pure air, and affirms that it diminifhes, both
with nitrous gas and common air.
h, I introduced into a vefTel containing 30
grains of platina, 2050 grains of aqua regia,
compofed of equal parts, by weighty of concen-
trated nitric acid of 1^43, and muriatic acid of
l,l6. At the common temperature^ that is^
49^, no aflion between the acid and platina
appeared to take place. On the application
of the heat of a fpirit lamp, the fohition gra-
dually became yellow red, and gas was given
out with rapidity. Some of this gas received
in ajar filled with warm water, appeared of a
bright yellow color. On agitation, the greater
part of it was abforbed by the water, and the
remainder extinguiflied flame. ¥/hen it was
received over mercury, it afled upon it with
great rapidity, and formed on the furface a
white cruft.
As the procefs of folution advanced, the
color of the acid changed to dark red, at the
fame time that the produdlion of gas was much
increafed ; more than 40 cubic inches were
foon colleded in the water apparatus.
( 224 )
Different portions of the gas were eKaminedj
it exhibited the following properties :
1. Its color was orange red,* and its fmell
exadly refembled that of oxygenated muriatic
acid.
2. When agitated in boiled water, it was
rapidly abforbed, leaving a refiduum of rather
more than one twelfth.
3. The taper burnt in it with increafed bril-
liancy, the flame being long, and deep red at
the edges.
4. Iron introduced into it ignited, burnt with
a dull red light.
5. Green vegetables expofed to it were in-
ftantly rendered white.
6. It underwent no diminution, mingled with
atmofpheric air.
7. When mingled with nitrous gas, it gave
denfc red vapor, and rapid diminution.
* This deep color depended, in fome meafurC; upon the
nitro-rauriatic vapor fufpended in it. I have lince obferved
that it is more intenfe in proportion as the heat employed
for the production of the gas has been ftronger. The
natural color of the peculiar gas is deep yellow.
( 225 )
c. jFrom the exhibition of thefe properties^
it was evident that the gas produced during the
folution of platina in aqua regia, chiefly con-
fifted of oxygenated muriatic acid, or of a gas
highly analogous to it. It was, however, dif-
ficult io conceive how a body, by combining
with a portion of the oxygene of nitro-muriatic
acid, could produce from it oxygenated muriatic
acid, apparently mingled with very fmall por-
tions of any other gas.
d. To afcertain whether any permanent gas
was produced during the ebullition of aqua
regia, of the fame compofition as that ufed for
the folution of the platina ; I kept a large quan-
tity of it boiling for fome time, in communica-
tion with the water apparatus ; the gas generated
appeared to be wholly nitro-muriatic, and was
abforbed as fafl as produced, by the water.
e. To determine whether any nitrous oxide
was mingled with the peculiar gas, as well as
the nature and quantity of the unabforbable gas,
nitrous gas was gradually added to 21 cubic
inches of the gas produced from a new folution^
P
^
( 226 )
till the diminution was complete : the gas re-
maining equalled 2,3 cubic inches ; it was
unabforbable by water, and extinguifhed flame.
In another experiment, when the the laft
portions of gas from a folution were carefully
received in water previoufly boiled, 12 cubic
inches agitated in water left a refiduum of 1.3 ;
whilft the fame quantity decompofed by nitrous
gas, containing ,02 nitrogcne, left about 1.5
Hence it appeared that the aeriform produdls
of the folution confifled of the peculiar gas
analogous to oxygenated muriatic acid^ and of
a fmall quantity of nitrogene.
/. Confequently a portion of the nitric acid
of the aqua regia had been decompofed ; but if
it had given oxygene both to the platina and
muriatic acid, the quantity of nitrogene evolved
ought to have been much more conflderable.
g. To afcertain if any water had been de-
compofed, and the nitrogene condenfed in the
folution by its hydrogene, to form ammoniac,
I faturated a folution with lime, and heated it^
but no ammoniacal fmell was perceived.
( 227 )
h. To determine if any nitrogene had entered
into chemical combination with muriatic acid
and oxygene, fo as to form an aeriform triple
compound, analogous in its properties to oxy-
genated muriatic acid, I expofed fome of the
gas to mercury, expelling that this fubftance^
by combining with its oxygene, would efFedl a
complete decompofition ; and this was a61ually
the cafe : for the gas was at firft rapidly dimin-
ifhed, and the mercury became oxydated ; its
volume, however, foon increafed ; and the
refidual gas appeared io be nitrous, mingled
with much nitrogene. The exa6l proportions
of each, from an accident, I could not deter-
mine.
This experiment was inconclufive, becaufe
the nitro-muriatic acid fufpended in the pecu-
liar gas, from which it can probably be never
perfedily freed, ad^ed in common with it upon
the mercury, and produced nitrous gas i and
this nitrous gas, at the moment of its produc-
tion, formed nitrous acid by combining with the
oxygene of the peculiar gas; and the nitrous
tfrtr I
( 228 )
acid generated ^ was again decompofed by the
niercLiry ; and hence nitrous gas evolved, and
poffibly Tome nitrogene.
/. Peculiar circumftances prevented me at
this time from completely inveftigating the
fubje^l. It remains doubtful whether the gas
confifts fimply of highly oxygenated muriatic
acid and nitrogene,-}- produced by the decom-
^ The decompofition of aeriform nitrous acid by mercury,
was firft noted by Prieftley 5 vol. iii. pag. 101. This decom-
pofition I have often had occafion to obferve. In reading
Humbolt's paper on eudiometry, Annales de Chimie, xxviii,
pag. 150, I vi^as not a little furprifed to find that he takes
no notice of this fad. He feems to fuppofe that nitrous
acid can remain aeriform, and even be condenfed, in con-
tad with mercury, without alteration. He fays, " In
mingling 100 parts of atmofpheric air with 100 of nitrous
air, the air immediately became red, but all the acid pro-
duced remained aeriform j and after eighteen hours fome
drops only of acid were formed, which fwam upon the
mercury."
f Lavoifier has faid concerning aqua regia, " In folu-
'* tions of metals in this acid, as in all other acids, the
" metals are firft oxydated, by attrading a part of the
" oxygene from the compound radical. This occafions the
'^ difengagement of a particular fpecies of gas not hitherto
" defcribed, which may be called nitro-rauriatic gas. It
( 229 )
pofition of nitric acid from the coalefcitig affin-
ities of platina and muriatic acid for oxygene ;
or whether it is compofed of a peculiar gas,
analogous to oxygenated muriatic acid, and
nitrogene, generated from fome unknown
affinities.-f*
XL On the aBion of the EleBric Spark on a
mixture of Nitrogene and Nitrous Gas,
Thinking it poffible that nitrous gas and
*' has a very difagreeable fmell^ and is fatal to animal life
" when refpired 5 it attacks iron, and caufes it to ruft 5 it
'' is abforbed in conliderable quantities by water,'' Elem.
Eng. 237.
t T have no doubt but that the gas procured from the
folution of gold in aqua regia, is analogous to that produ-
ced from platina.
Some very uncommon circumftances are attendant on the
folution of platina :
1ft. The iramenfe quantity of acid required for the folu-
tion of a minute quantity of platina.
2d. The great quantity of gas produced during the folu-
tion of this minute quantity.
3d. The intenfe red color of the folution, and its per-
fedly acid properties after it ceafes to a6t upon the metal.
( ISO )
nitrogene might be made to combine^ by the
adion of the eledlric fpark, fo as to form nitrous
oxide, I introduced 20 grain meafures of each
of them into a fmall detonating tube^ graduated
to grains, (landing over mercury, and con-
taining a very fmail quantity of cabbage juice
rendered green by an alkali. After eledlric
fparks had been pafled through the gafes for an
hour and half, they were diminiftied to about
32, and the cabbage juice was flightly red-
dened. On introducing about 10 meafures of
hydrogene, and paffing the eleflric fpark
through the whole, no inflammation or dimi^
nution was perceptible. Hence the condenfa-
tion mofl probably arofe wholly from the forma-
tion of nitrous acid,* by the morp intimate
union of the oxygene of nitrous gas with fome
of its nitrogene, as in the experiments of
Prieftley.
As the nafccnt nitrogene, in the decompo-
* For if nitrous oxide had been formed, it would haye
leen decompofed by the hydrogene.
( 231 )
fition of nitrate of ammoniac, combines with a
portion of oxygene and nitrogene, to form
nitrous oxide ; it is probable that nitrous oxide
may be produced during the paflage of nitrous
gas and ammoniac through a heated tube.
XIL Genernl Remarks,
There are no reafons for fuppofing that ni-
trous oxide is formed in any of the procefles of
nature; and the nice equilibrium of affinity by
which it is conftituted, forbids us to hope for the
power of com pofing it from its fimple princi-
ples. We muft be content to produce it,
either diredlly or indired^ly, from the decom-
pofition of nitric acid. And as in the decom-
pofition of nitrate of ammoniac, not only all the
nitrogene of the nitric acid enters into the com-
pofition of the nitrous oxide produced, but
likewife that of the ammoniac, this procefs
is by far the cheapeft, as well as the moft expe-
ditious. A mode of producing ammoniac at
( 232 )
little expence, has been propofed by Mr. Watt.
Condenfed in the fulphuric acid, it can be
eafily made to combine with nitric acid, from
the decompofition of nitre by double affinity.
And thus, if the hopes which the experiments at
the end of thofe refearches induce us to indulge,
do not prove fallacious, a fubftance which has
been heretofore almoft exclufively appropriated
to the deftrudlion of mankind, may become, in
the hands of philofophy, a means of producing
health and pleafurable fenfation.
RESEARCH II.
INTO THE COMBINATIONS OF
NITROUS OXIDE,
AND ITS
DECOMPOSITION
BY
COMBUSTIBLE BODIES.
RESEARCH II.
DIVISION I.
EXPERIMENTS and OBSERVATIOUS on tbc
COMBINATIONS of NITROUS OXIDE,
!. Combination of Water with Nitrous Oxide,
a. A HE difcoverer of nitrous oxide firft
oblerved its folubility in water ; and it has
fince been noticed by different experimen-
talifts.
Dr. Prieftley found that water diflblved about
one half of its bulk of nitrous oxide, and that at
the temperature of ebullition, this fubftance was
incapable of remaining in combination with it.*
■'^ Experiments and obfervations, vol. ii. pag. 81.
( 236 )
h, I introduced to 9 cubic inches of pure
water^ i. e. water diftilled under mercury, 7
cubic inches of nitrous oxide, which had been
obtained over mercury, from the decompofition
of nitrate of ammoniac, and in confequence was
perfectly pure. After they had remained toge-
ther for 1 1 hours, temperature being 46°, during
which time they were frequently agitated, the
gas remaining was 2,3 ; confequently 4,7 cubic
inches had been abforbed. And then, 100
cubic inches, ::=: 25300 grains of water, will
abforb 54 cubic inches, =27 grains, of nitrous
oxide.
c» The tafte of water impregnated with
nitrous oxide, is diftindlly fvveetifh ; it is fbfter
than common water, and, in my opinion, much
more agreeable to the palate. It produces no
alteration in vegetable blues, and efFet5^s no
change of color in metallic folutions.
d. Thinking that water impregnated with
nitrous oxide might probably produce fome
effefls when taken into the ftomach, by giving
out its gas, I drank, in June, 1799^ about
( 237 )
3 ounces of it^ but without perceiving any
effefls.
A few days ago, confidering this quantity as
inadequate, I took at two draughts nearly a
pint, fully faturated ; and at this time Mr.
Jofeph Prieftley drank the fame quantity.
We neither of us perceived any remarkable
efFedls.
Since that time I have drank near three pints
of it in the courfe of a day. In this inftance it
appeared to a6l as a diuretic^ and I imagined
that it expedited digeftion. As a matter of
tafte, 1 fhould always prefer it to common
water.
e. Two cubic inches of pure water, that had
been made to abforb about 1,1 cubic inches of
nitrous oxide ; when kept for fome time in
ebullition, and then rapidly cooled, produced
nearly I of gas. Sulphur burnt in this gas with
a vivid rofe-colored flame.
In another experiment, in which the gas
was expelled by heat from impregnated water,
and abforbed again after much agitation on
( 238 )
cooling ; the refiduum was hardly perceptible^
and mod likely depended upon fome gas which
had adhered to the mercury, and was liberated
during the ebullition. Hence it appears that
nitrous gas is expelled unaltered from its aqueous
folution by heat.
/. I have before mentioned, Divifion III^
that nitrous oxide, during its combination with
fpring water, expels the common air diflblved
in it. This common air generally amounts to
one fixteenth, the volume of the water being
unity. A corredlion on account of this circum-
ftance mull be made for the apparent deficiency
of diminution, and for the common air mingled
in confequence, with nitrous oxide during its
abforption by common water.
g. Water impregnated with nitrous gas ab-
forbed nitrous oxide ; but the retidual gas was
much greater than that of common water, and
gave red fumes with atmofpheric air. Nitrous
gas agitated for a long while over water highly
impregnated with nitrous oxide, was not in the
fliightefl degree diminiflied, in one experiment
indeed it was rather increafed j doubtlefs from
( 239 )
the liberation of fome nitrous oxide from the
water by the agitation.
h. Nitrous oxide kept in contadi with aque-
ous folution of fulphurated hydrogene and often
agitated, was not in the flighteft degree dimi-
nifhed.
Sulphurated hydrogene, introduced into a
folution of nitrous oxide, was rapidly abforbed,
and as the procefs advanced, the nitrous oxide
was given out.
u Water impregnated with carbonic acid,
poflefled no acSion upon nitrous oxide, and did
not in the flighteft degree abforb it. When
carbonic acid was introduced to an aqueous
folution of nitrous oxide ; the aeriform acid was
abforbed, and the nitrous oxide liberated.
h. From thefe obfervations it appears that
nitrous oxide has lefs affinity for water, than
even the weaker acids, fulphurated hydrogene
and carbonic acid ; as indeed one might have
conjeflured a priori from its degree of folubility :
likewife that it has a ftronger attra61ion for
water than the gafes not pofTefled of acid or
( 240 )
alkaline properties ; it expelling from water
nitrous gas, oxygcne, and common air ; proba-
bly hydro-carbonate^ hydrogene, and nitrogene.
li. Combinations of Nitrous Oxide with
Fluid Inflammable Bodies.
a. Vitriolic ether abforbs nitrous oxide
in much larger quantities than water.
A cubic inch of ether, at temperature 52®,
combined with a cubic inch and feven tenths of
nitrous oxide.
Ether thus impregnated was not at all altered
in its appearance ; its fmell was precifely the
fame, but the tafte appeared lefs pungent, and
more agreeable. Nitrous oxide is liberated
unaltered from ether at a very low temperature,
that is, at about the boiling point of this fluid.
For expelling nitrous oxide from impregnated
ether, and for afcertaining in general the quan-
tity of gafes combined with fluids, I have lately
made ufe of a very Ample method, which it
may not be amifs tg defcribe.
( 241 )
The impregnated fluid is introduced into a
fmall thin tube, graduated to ,05 cubic inches^
through mercury. The quantity of fluid fhould
never equal more than a fifth or fixth of the
capacity of the tube.
The lower part of the tube is adapted to an
orifice in the Ihelf of the mercurial apparatus,
fo as to make an angle of about 40^ with the
furface of the mercury.
The flame of a fmall fpirit lamp is then
applied to that part of the tube containing the
fluid ; and after the expulfion of the gas from
it, the heat is raifed fo as to drive out the fluid
through the orifice of the tube. Thus the
liberated gas is preferved in a flate proper for
accurate examination.
Impregnated ether, during its combination
with water, gives out the greater part of its
nitrous oxide. During the liberation of nitrous
oxide from ether, by its combination with water,
a very curious phaenomenon takes place.
If the water employed is colored, fo that it
may be feen in a flratum diftindt from the im-
Q
( 242 )
pregnated ether, at the point of contai^ a num-
ber of fmall fpherules of fluid will be perceived,
apparently repulfive both to water and ether ;
thefe fpherules become gradually covered with
minute globules of gas, and as this gas is
liberated from their furfaces, they gradually dif-
appear.
h. Alcohol diflblves confiderable quantities of
nitrous oxide.
2 cubic inches of alcohol, at 52^, combined
with 2,4 cubic inches of nitrous oxide. The alco-
hol thus impregnated had a tafte rather fweeter
than before, but in other phyfical properties
was not perceptibly altered.
Nitrous oxide is incapableof remaining in com-
bination with this fluid at the temperature of ebul-
lition ; it is liberated from it unaltered by heat.
Impregnated alcohol, during its combination
with water, gives out the greater part of its com-
bined nitrous oxide : on mingling the two fluids
together, at the point of contadl the alcohol
becomes covered with an infinite number of
fmall globules of gas, which continue to be
( 243 )
generated during the whole of the combination^
and in paiRng through the fluid render it ahuoft
opaque.
c. The eflential oils abforb nitrous oxide to
a greater extent than either alcohol or ether.
,5 cubic inches of oil of i^arui combined with
^fi cubic inches of nitrous oxide at 51^. The
color of the oil thus impregnated was rather
paler than before.
Nitrous oxide is expelled unaltered from im-
pregnated oil of carui, by heat.
1 of oil of turpentine abforbed nearly 2 of
nitrons oxide, at 57°. Its properties were not
fenfibly altered from this combination, and the
gas was expelled from it undecompounded, by
heat.
d. As well as the efTential oils, the fixed oils
diflblve nitrous oxide at low temperatures, whilft
at high temperatures they do not remain in com-
bination.
1 of olive oil abforbed, at 6P, 1,2 of nitrous
oxide, but without undergoing any apparent
phyfical change.
( 244 )
III. A^ion of Fluid Acids on Nitrous Oxide.
a. Nitrous oxide expofed to concentrated
fulpburic acid, undergoes no change, and fuf-
fers no diminution, that may not be accounted
for from the abftradlion of a portion of its water
hy the acid.
h. Nitrous oxide is fcarcely at all foluble in
nitrous acid, and expofed to that fubftance,
undergoes no alteration.
c. Muriatic acid, of fpecific gravity 1,14
abforbs about a third of its bulk of nitrous oxide.
It fufFers no apparent change in its properties
from beingthus impregnated, and the gas is again
given out from it on the application of heat.
d. Acetic acid abforbs nearly one third of
its bulk of nitrous oxide.
e. Aqua regia, that is, the nitro-muriatic
acid, abforbs a very minute portion of nitrous
oxide.
/. Nitrous oxide was expofed to a new com-
pound acid, conlifting of oxygenated muriatic
acid, and fulphuric acid, which I difcovered in
( 245 )
July,, 1799) and of which an account will be
fhortly publifhed; but it was neither abforbed or
altered.
I have before mentioned that the aqueous
foUitionsof fulphurated hydrogene and carbonic
acid, neither diflblve or alter nitrous oxide.
IV. AS'ion of Saline Solutions^ and other
SuhftanceSy on Nitrous Oxide,
a. Nitrous o^cide expofed to concentrated
folution of green fulphate of iron, at 58°, un-
derwent no perceptible diminution ; not even
after it had been fufFered to remain in contadl
with it for half an hour.
h. It underwent diminution of nearly ,2 when
agitated in contadl with a folution of red ful-
phate of iron, the volume of the folution being
unity.
c. Solution of green fulphate of iron, fully
impregnated with nitrous gas, did not in the
flighteft degree abforb nitrous oxide, and ap-
peared to have no adlion upon it.
( 246 )
d. Solution of green muriate of iron, whe-
ther impregnated with nitrous gas, or unim-
pregnated, has no affinity for, or adion upon,
nitrous oxide,
€, Solution of red muriate of iron in alcohol,
abforbed nearly one fifth of its bulk, of nitrous
oxide.
/. . Solution of pruffiate of potafh abforbed
nearly one third of its volume, of nitrous oxide,
which was again expelled from it by heat.
g. Solution of nitrate of copper appeared to
have no affinity for nitrous oxide.
h. Concentrated folution of nitrate of am-
moniac, at 58^, abforbed one eighth of its bulk
of nitrous oxide.
/. Solutions of alkaline fulphures abforb
nitrous oxide in quantities proportionable to
the water they contain ; it is expelled from
them unaltered by heat. None of the hydro-
fulphures diflblve more than half their bulk of
nitrous oxide.
k. Concentrated folutions of the fulphites
poflefs little or no a6lion on nitrous oxide :
(247 )
diluted folutions abforb it in fmall quantities,
/. Concentrated folution of muriate of tin
abforbs about one eighth of nitrous oxide ;
more dilute folutions abforb larger quantities.
From thefe obfervations we learn, that neutro-
faline folutions in general, have very feeble
attractions for nitrous ojxide ; and as folutions of
green muriate, and fulphate of iron, whether free
from nitrous gas, or impregnated with it, poilefs
no adlion upon nitrous oxide, nitrous gas may be
feparated from this fubftance by thofe folutions
with greater facility than nitrous oxide can be
feparated from nitrous gas, by water or alcohol.
Charcoal abforbs nitrous oxide as well as
all other gafes ; and it is difengaged from it
by heat.
I have as yet found no other folid body, not
poflefled of alkaline properties, capable of ab-
forbing nitrous oxide in any flate of exiflence.
The bodies poffefling the flrongeft ailinity
for oxygene, the dry fulphites, muriate of tin,
the common fulphures, white prufliate of potafh,
and green oxide of iron, do not in the flighteft
( 248 )
degree aft on nitrous oxide at common tem-
peratures.
V, A3'ton of different Gafes on Nitrous
Oxide,
a. 12 meafures of muriatic acid gas were ming-
led with 7 meafuresof nitrous oxide at 56**. After
remaining- together for a minute, they filled a
fpace equal to IQ^ meafures. When water
was introduced to them, the muriatic acid was
abforbed much more flowly than if it had been
unmingled.
In another experiment, when the gafes were
faturated with water, 9 meafures of each of
them, when mingled and fufFered to remain in
contadl for a quarter of an hour, filled a fpace
nearly equal to 19 ; and after the muriatic acid
had been abforbed by potafh, the nitrous oxide
remained unaltered in its properties.
From the expanfion, it appears mofl proba-
ble that aeriform muriatic acid, and nitrous
oxide, have a certain affinity for each other, and
( 249 )
that they combine when mingled together ; for
jn the laft/ experiment, the increafe of volume
cannot be accounted for by fuppofing that ni-
trous oxide undergoes lefs change of volume
than muriatic acid, by aeriform combination
with water, and that the expaniion depended
upon the folution of fome of its combined water
by the muriatic acid. That muriatic acid and
nitrous oxide have a flight affinity for each
other, likewife appears from the abforption of
nitrous oxide by aqueous folution of muriatic
acid.
Thinking that nitrous oxide might attraft
muriatic acid from its folution in water, I ex-
pofed a minute quantity of fluid muriatic acid
to nitrous oxide ; but no alteration of volume
took place in the gas.
b. 6 meafures of nitrous oxide were mingled
with 1 1 meafures of fulphureous acid, faturated
with water ; after remaining at reft for fix
minutes, they filled a fpacc nearly equal to 18
meafures. Expofed to water, the fulphureous
acid was abforbed, but not nearly fo rapidly as
( 250 )
when itl a free ftate. Sulphur burnt with a
vivid flame in the refidual nitrous oxide. 7
meafures of fulphureous acid were now mingled
with 8 of nitrous oxide. They filled a fpace
nearly equal to 15|, and no farther expanfion
took place afterwards.
From thefe experiments it appears probable
that fulphureous acid, and nitrous oxide, have
fome affinity for each other.
c. 1 1 meafures of carbonic acid were mingled
with 8 of nitrous oxide ; they filled a fpace
nearly equal to ig meafures. On expofing the
mixture to cauftic potafh, the carbonic aeid was
abforbed, and the nitrous oxide remained pure.
Hence it appears that carbonic acid and nitrous
oxide do not combine with each other.
d Oxygenated muriatic acid, and nitrous
oxide, were mingled in a water apparatus : there
was a flight appearance of condenfation ; but
this was mod probably owing to abforption by
the water ; on agitation, the oxygenated muri-
atic acid was abforbed, and the greater part of
the nitrous oxide remained unaltered.
( ^51 )
e. Sulphurated hydrogene and nitrous oxide,
mingled together, neither expanded or con-
trail ed ; expofed to folution ot potafh, the acid*
only was abforbed.
/. 10 meafures of nitrous gas were admitted
to 12 of nitrous oxide at 59°. They filled a fpac6
equal to 22, and after remaining together for
an hour, had undergone no change. Solution
of muriate of iron abforbed the nitrous gas
without affecting the nitrous oxide.
g. Nitrous oxide was fucceflively mingled
with oxygene, atmofpheric air, hydro-carbonate,
phofphoratcd hydrogene, hydrogene, and nitro-
gene, at 57^ ; it appeared to poflefs no aflion
on any of them, and was feparated by water,
the gafes remaining unaltered.
h. As nitrous oxide was foluble in ether,
alcohol, and the other inflammable fluids, it
was reafonablc to fuppofe that its affinity for
thofe bodies would enable them to unite with
* The experiments of Berthollet have clearly proved
the perfect acidity of this fubftance.
( 252 )
it in the aeriform ftate. At the fuggeftion of
Dr. Beddoes I made the following experiment:
To ]2 meafures of nitrous oxide, at 54°, I
introduced a fingle drop of ether ; the gas im-
mediately began to expand, and in four minutes
filled a fpace equal to lixteen meafures and a
quarter. When an inflamed taper was plunged
into the gas thus holding ether in folution, a
light blue flame flowly pafl"ed through it.
A conflderable diminution of temperature is
moil probably produced, from the great ex-
panflon of nitrous oxide during its combination
with ether.
A drop of alcohol was admitted to 14 mea-
fures of nitrous oxide. In five minutes, the
gas filled a fpace equal to fifteen and a third ;
but no farther diminution took place afterwards.
A minute quantity of oil of turpentine was
introduced to 14 meafures of nitrous oxide ; it
filled, in 4 minutes, a fpace rather lefs than 14;
and no farther change took place afterw^ards.
Mod likely this contra6lion arofe from the pre-
cipitation of the water diflblved in the gas by
( 253 )
the ilronger affinity of the oil for nitrous
oxide. To afcertain with certainty if any oil
had been diflblved by the gas, I introduced
into it a fmall quantity of ammoniac. It imme-
diately became llightly clouded, moft probably
from the formation of foap, by the combination
of the diflblved oil with tlfe ammoniac.
From thefe experiments we learn, that when
nitrous oxide is mingled with either carbonic
acid, oxygene, common air, hydro-carbonate^,
fulphurated hydrogene, hydrogene, or nitro-
gene, they may be feparated from each other
without making any allowance for contraclion
or expanfion : but if a mixture of either muri-
atic acid, or fulphureous acid gas, with nitrous
oxide, is experimented upon ; in the abforption
of the acid by alkalies, the apparent volume of
gas condenfed will be lefs than the real one, by
a quantity equal to the fum of expanfion from
combination. Confequently a corredtion muft
be made on account of this circumflance.
Though alcohol, ether^ effential oils, and the
fluid inflammable bodies in general; diflj>lve
( 254 )
nitrous oxide with much greater rapidity than
water, yet as we are not perfedly acquainted
with their adlion on unabforbable gafes, it is
better to employ water for feparating nitrous
oxide from thefe fubftances ; particularly as that
fluid is more or lefs combined with all gafes^
and as we are acquainted with the extent of its
adlion upon them.
By purfuing the fubjecS of the folution of
ellential oils in gafes, we may probably difcover
a mode of obtaining them in a ftate of abfolute
drynefs. For if other gafes as well as nitrous
oxide, have a ftronger affinity for oils than for
water, water mofi: probably will be precipitated
from them during their folution of oils ; and
after their faturation with oil, it is likely that
they are capable of being deprived of that fub-
llance by ammoniac.
VI. Jl&ton of aeriform Nitrous Oxide on the
Alkalies, History of the discovery of the combina-
tions of Nitrous Oxide with the Alkalies,
a. When nitrous oxide in a free ftate is
( 265 )
expofed to the folid cauftic alkalies and alka-
line earths, at common temperatures, it is nei-
ther abforbed nor adled upon ; when it is placed
in contad with folutions of them in water, a
fmall quantity is diflolved ; but this combina-
tion appears to depend on the water of the folu-
tion, for the gas can be- expelled unaltered, at
the temperature of ebullition.
h, Cauftic potafh was expofed to nitrous
oxide for 13 hours : the diminution was not to
one fiftieth, and this flight condenfation niofi:
probably depended upon its combination with
the water of the gas.
Concentrated foluticn of potafh - abforbed
a fourth of its bulk of nitrous oxide. When
the impregnated iblution was heated, globules
of gas were given out from it rapidly ; but the
quantity colled^ed was too fmall to examine.
Soda, whether folid or in folution, exhibited
exaflly the fame phsenomena with nitrous oxide.
The folution of foda abforbed near a quarter of
its bulk of gas.
A 11 meafures of ammoniacal gas were
( 256 )
mingled with 8 meafures of nitrous oxide over
dry mercury, both of the gafes being faturated
with water. No change of appearance was
produced by the mixture, and they filled, after
two minutes, a fpace equal to ig. On the in-
trodu<Slion of a little water, the ammoniac was
abforbed, and the nitrous oxide remained un-
altered, for it was diflblved by water as rapidly
as if it had never been mingled with ammo-
niac*
7 meafures of nitrous oxide, expofed to 6
meafures of folution of ammoniac in water, was
in an hour diminifhed to 4j nearly. When
the folution was heated over mercury, permanent
gas was produced, which was unabforbable by
a minute quantity of water, and foluble in a
large quantity ; confequently it was nitrous
oxide.
* The Dutch chemifts have aflerted, that mixture with
ammoniac prevents the abforption of nitrous oxide by wa-
ter, either wholly or partially. Journal de Phyfique,
t. xliii. part ii. pag. 327. It is difficult to account for
their miftake.
( ^57 )
d. Nitrous oxide was expofed to dry cauftic
ftrontian ; it underwent a diminution of nearly-
one fortieth, which mod. likely was owing to
the combination of the ftrontian with its water,
1 1 meafures of nitrous oxide were agitated
in conta6l with 8 of flrontian lime water : nearly
4 meafures were abforbed. The impregnated
folution expofed to heat, rapidly gave out its
gas ; 3 meafures were foon collecS^ed, which
rhingled with a fmall quantity of hydrogene,
and inflamed by the taper, gave a fmart deto-
hation.
e. Nitrous oxide expofed to lime and argil,
both wet and dry, was not in the flightefl de-
gree adled upon.
From thefe experiments it is evident that
nitrous oxide in the aeriform ftate cannot be
combined either with the alkalies, or the alka-
line earths. That a combination may be efFefled
between nitrous oxide and thefe fubftances, it
muft be prefented to them, in the nafcent Jlate.
The falts compofed of the alkalies and nitrous
oxide, are not analogous to any other compound
R
( 253 >
fubilances, being pofleffed of very Angular pro-
perties. Before thefe properties are detailed, it
may not be amifs to give an account of the
accidental way in which I difcovcred the mode
of combination.
In December, 1 799, defigning to make »
very delicate experiment, with a view to
afcertain if any water was decompofed du-
ring the converfion of nitrous gas into nitrous
oxide, by fulphite of potafh, I expofed 200
grains of cryflalifed fulphite of potafh, con-
taining great fuperabun dance of alkali, to 14
cubic inches of nitrous gas, containing one
eighteenth nitrogenef. The alkali was em-
ployed to preferve any amnopniac that might be
formed, in the free ftate, as it would otherwife
combine with fulphureous acid.*
The volume of gas diminifhcd with great
rapidity ; in two hours and ten minutes it was
* Sulphureous acid faturates more potafh than fulphuric
acid, fo that moft probably during the convcrlion of ful-
phite of potafh into fulphate, portions of fulphureous acid
aro difcngaged.
( ^59 )
reduced to 6-, which I confidered as the limit
of diminution. Accidentally, however, fufFer-
ing it to remain for three hours longer, I was
much furprifed by finding that not quite 12
cubic inches remained, which confifted of
nitrous oxide^ mingled with the nitrogene that
exifted before the expei'iment.
In accounting theoretically for this phaeno-
menon, different fuppofitions necefTarily pre-
fented themfelves.
\i\, It was pofBble, that though fulphite of pot-
afh, and potafh, feparately poffefTed no adf ion on
free nitrous oxide, yet in combination they might
exert fuch affinities upon it as either to abforb
it, or make it enter into new combinations.
2dly. It was more probable that the eauftic
potafh, though incapable of condenfing aeriform
nitrous oxide, was yet poffefTed of a f^rong
affinity for it when in the najcent Jlate, and that
the nitrous oxide condenfed in the experiment
had been combined in this ffate with the free
alkali.
To afcertain if the compound of potafh and
( 'ido j
folphite of potadi with fulphatc, was capable of
a6ling upon nitrous oxide, I fuffered a quan-
tity of this fubftance to remain in conta6l with
the gas for near a day : no change whatever
took place.
To determine whether the diminution of
nitrous oxide depended upon its abforplion in
the nafcent (late, by the peculiar compound of
potafh and fulphite of potafh, or if it was fimply
owing to the alkali.
I mingled a folution of fulphite of potafh with
cauftic foda ; the fait, after being evaporated at
a low temperature, was expofed to nitrous gas.
The nitrous oxide formed was abforbed, but
in rather lefs quantities than when alkaline
fulphite of potafh was employed.
Hence it was evident that the alkali was the
agent that had condenfed the nitrous oxide in
thofe experiments, for foda is incapable of com-
bining either with fulphate, or fulphite of pot-
afh.
To afcertain whether any change in the con-
ftitution of the nitrous oxide had been produced
( 261 )
by the condcnfation, I introduced a fmall quan-
tity of fulphite of potafh, with excefs of alkali,
that had abforbed nitrous oxide, into a long
and thin cylindrical tube filled with mercury ;
and inclining it at an angle of 35^ with the
plane of the mercury, applied the heat of a fpirit
lamp to th^t part of the tube containing the
falts ; when the glafs became very hot, gas was
given out wit1i rapidity ; in lefs than a minute
the tiibe was full. This gas was transfered.into
another tube, and examined; it proved to be
nitrous oxide in its higheft ftateof purity;* for
a portion of it abforbed by common water, left
no more than a refiduum of y^, and fulphur
burnt in it with a vivid rofe-colored flame.
Being now fatisfied that the alkalies were
capable of combining with nitrous oxide; to
inveftigate with precifion the nature of thefe
new compounds, I proceeded in the follovving
manner.
* Hence we learn that fulphite of polaflj, when ftrongly
heated; does not decorapofc nitrous oxide, even ia
the naf cent Jim c .
( 262 )
VII. Combination of Nitrous Oxide voith
fotafJj,
a. Into a folutlon of falphite of potadi, which
had been made by palfing fulphureous acid gas
from a mercurial airholder into cauftic potafh
dillblved in water, I introduced 17 grains of
dry potafh. The whole evaporated at a low
temperature, gave 143 grains of fait. This fait
was not wholly compofed of fulphite of potafh
and potadi ; it contained as well, a minute quan-
tity of carbonate, and fulphate of potafh, formed
during the evaporation.*
120 grains of it finely pulverifed, and retain-
ing the water of cryflalifation, were expofed
to 15 cubic inches of nitrous gas, over mercury.
The nitrous gas diminiOied with great rapidity,
and in three hours a cubic inch and nine tenths
•'•^' See the excellent memoir of Fourcioy and Vaiiquelin
on the fulphureous acid, and its combinations. Annales do
Chimie, ii, 54. Or Nicholfon's Phil. Journal; vol. i,
pag. 313.
( 263 )
only remained, which confifled of nearly otit
third nitrous oxide, and two thirds nitrogene
that had pre-exifted in the nitrous gas. The
increafe of weight of the fait could not be deter-
mined, asfome of it was loft by adhering to the
vellel in which the combination was effedled,
and to the mercury. It prefented no diflindl
feries of cryftalifations, even when examined by
the magnifier; rendered green vegetable blues,
and its tafte was very different from that of the
remaining quantity of fait that had been expofed
to the atmofphere. A portion of it ftrongly
heated over mercury, gave out gas with great
rapidity, which had all the properties of the
pureft nitrous oxide.
When water was poured upon fome of it, no
• gas was given out, and the whole was equably
and gradually diffolvcJ. Alcohol, as well as
ether, appeared incapable of diflblving any part
of it.
When muriatic acid was introduced into it,
confined by mercury, a rapid effervefccnce took
.plaice. Part of the gas difengaged was futphu-
( 264 )
reous acid, and carbonic iciH . fK
^as nitrous oxide. "''"''' ^'^^ ''^•"-nde,
J. '-^^ean„,berofexperia,entsupo„
^alt procured in, hcanner I have Mde
^-bed,w.havievvtoobtainU.co.p„d;
nitrous oxide and Dot^(h r r '
S mat hlllo or no gas was gi.en oM
•l.«»mb,„a„„„„f„i,„,„„^,_, ■ -
1^ ^nn, ya the extreme and n^arlv
^2c-P--.y rop.™i„, ,^„„ ,„,„ ^^;
% 0,p„„„j, ,„,„.„^^_
( 265 )
wholly converted into fiilphate ; and after the
reparation of this by folution^ evaporation, and
cryftalifation, at a low temperature, I obtained
the new combination, mingled with very little
carbonate ofpotafh, and flill lefs of fulphite.
The minute quantity of fulphite chiefly ap-
peared in very fmall cryftals ; diilint^ from the
]mafsoffalt, which poilefTed no regular cry f-
talifation, and was almoft wholly compofed of
the new compound, intimately mingled with
a little carbonate. The new compound, as
nearly as as I could eftimate frqm the quantity
of nitrous oxide abforbed, confided of about
3 alkali, to 1 of nitrous oxide, by weight.
It exhibited the following properties :
1. Its tafle was cauftic, and poilefled of a pun-
gency different from either potafh or carbonate
ofpotafh.
2. It rendered vegetable blues green, which
might poflibly depend upon the carbonate of
potafli mixed with it.
3. Pulverifed charcoal mingled with a few
grains of it, and inflamed, burnt with flight
{ 266 )
fcintillations. Projected into zinc in a ftatc of
fufion, a flight inflamination was produced.
4. When either fulphuric, muriatic, or
nitric acid was introduced to it under mercury,
it gave out nitrous oxide, mingled with a little
carbonic acid.
5. Thrown into a folution of fulphurated
hydrogene, gas was difengaged from^it, but in
quantities too minute to be examined.
6. When carbonic acid was thrown into a
folution of it in water, gas was difengaged ;
on examination it proved to be nitrons oxide.
7. A ^concentrated folution of it kept in
ebullition in a cylinder, confined by mercury,
gave out a few globules of gas, which were too
minute to be examined, and probably confifted
of common air previoufly contained in the
water.
c. In the experiments made toafcertain thefe
properties all the fait was expended, otherwife I
fhould have endeavoured to afccrtain what quan-
tity of gas would have been liberated by heat from
a given weight ; and likewife what would have
( ^67 )
been the efFe6ls of admixture of It with oil.
When fome of the mixed fait was mingled with
oil of turpentine, part of it was diflblvedj and
the fluid became white ; but no gas was given
out. On this coarfe experiment, however, I
cannot place much dependance. If the com-
bination of nitrous oxide and potafh is capable
of combining with oil without decompoiition,
barytcs and ftrontian* will probably feparate the
oil from it, and thus it may poffibly be obtained
in a ftate of purity.
In a rough experiment made on the conver-
fion of nitrous gas into nitrous oxide, by con-
centrated folution of fulphite of potaOi with
excefs of alkali, very little of the nitrous oxide
was abforbed. Hence It is probable that water
leflTens the affinity of potafh for nafcent nitrous
oxide. ^ '
* Unlefs the fum of affinity of the potalli, oil, nitrous
oxide, and earths, fhould be fnch as to enable the nitrous
oxide to combine with the earth, whilft the oil and alkali
jremained iu combination, &c..
( 268 )
VIII. Combination of Nitrons Oxide with
Soda,
The union of nitrous oxide with foda is
cfFe6led in the fame manner as with potafh.
The alkali, mingled by folution and evaporation,
with either fulphite of foda, or of potafh, is ex-
pofed to nitrous gas ; the nitrous oxide is con-
denfed by it at the moment of generation, and
the combination efFed^ed.
As far as I have been able to obferve, nitrous
oxide is not abforbed to fo great an extent by
foda, as potaHi.
I have not yet been able to obtain the com-
bination of nitrous oxide with foda in its pure
ftate. To the attainment of this end, difficul-
ties identical with thofe noticed in the lafi: fec-
tion prefent themfelvcs. It is extremely difficult
to procure the foda perfectly free from carbonic
acid, and though by ufing fulphite of potafh the
fulphate formed is eafily feparated, yet flill evapo-
r^ion and cryftalifation will not difengagc i\\^
(26g)
fafphite and carbonate from the new com-
pound.
The compound of foda and nitrous oxide,
mingled with a little fulphite and carbonate of
foda, was rapidly foluble, both in warm and
cold water, without efFervefcence. Its folution,
heated to ebullition, gave out no gas. The
tafte of the folid fait was cauftic, and more
acrid than that of the mixture of carbonate and
fulphite of foda. V7hen caft upon zinc in
fufion, it burnt with a white flame. When
heated to 40O or 500^, it gave out nitrous
oxide with rapidity. Nitrous oxide was ex-
pelled from it by the fulphuric, muriatic, . and
carbonic acids, 1 believe, by fulphurated
hydrogene,^
IX. Combination of Nitrous Oxide with
AmmoniaCi
I attempted to eiFedt this combination by
* For when a little of the mixed fait was introduced into
a folution of fulphurated hydrogene, globules of gas were
given out during the folution.
( ^70 )
converting nitrous gas into nitrous oxide, hj
fulphite of ammoniac, wetted with flrong folu-
tion of cauftic ammoniac ; but without fuccefs ;
fpr the whole of the nitrous oxide produced
ijCniained, in a free ftate.
Whea Jexpofed fulphite of potaOi, mingled
by folutipn apd evaporation with highly alkaline
carbonate of ammoniacj-l^ to nitrous gas, the
dirpinutiou was nearly one fourth more than if
pure fulphite of potafh had been employed.
IJence it appears moft likely that ammoniac is
capable of combination with nitrous oxide in the
nafgent (lajte. ,
. In the experiments on the converfion of ni-
trous gas into nitrous oxide, by nafcent hydro-
gene, and by fulphurated hydrogene, Ref. L
Divif V. probably the water formed at the fame
f Carbonate of ammoniac formed at a high tempera-
ture, containing near 6o per cent alkali, and capable of
combining with fmall quantities of acids without giving
out its carbonic acid. Of this fait a particular account will
be given in the experiments on the aramoniacal falts, which
I have often mentioned in the courfe of this work.
(271 )
time with the ammoniac and nitrous oxide, pre-
vented them from entering into combination ;
pojfihly the peculiar compound was formed, but
in quantities fo minute as not to be diftinguifhed
from fimple ammoniac ;*' for even the exiilence
of ammoniac in thefe proceiles, is but barely
perceptible.
If it fhould be proved by future experiments^
that in the decompofition of nitrous gas by
nafcent hydrogene, a peculiar compound of
nitrous oxide, water and ammoniac, is formed,
it will afford proofs in favor of the do61rine
of predifpofi ng affinity \\ for then this decom-
* It may not be amifs to mention fome appearances taking
place in the decompofition of nitrous gas by fuJpburated
hydrogepe, though it is vlfelefs to theorife concerning thera.
The fulphur depofited is at firft yellow j as the procefs pro-
ceeds, it becomes white, and in fome inftances I have fuf-
pe6ted a diminution of it.
t Predifpoling affinity, the exiflence of which at iirfl:
confideration it is difficnlt to admit, may be easily accounted
for by fuppofing the attractions of the fimple principles of
compound fubftances- And this do6trine will apply in all
^
rsTK^msesmmfif^B*
( ^72 )
pofition might be fuppofed to depend upon thfc'
difpofition of oxygene, hydrogene and nitro-
gene to alTunfie the Hates of combination in
which they might form a triple compound, of
water, nitrous oxide, and ammoniac.
Nitrous oxide might probably be made to
combine with ammoniac by expofing a mixture
of nitrous gas and aeriform ammoniac, to the
fulphites.
It is probable that nitrous oxide may be com-
bined with ammoniac, by means of double
affinity. Perhaps fulphate of ammoniac and
the combination of potafh with nitrous oxide
mingled together in folution, would be con-
verted into fulphate of potafh and the com-
pound of nitrous oxide, and ammoniac.
inftances where the conftitution of bodies is known. Pre-
difpofing affinity ought not to be confidered as the affinity of
non-exifiing bodies for each other j but as the mutual
affinity of their fimple principles, difpofing them to alTume
new arrangements.
( 273 )
X. Probability of forming Compounds of
Nitrous Oxide and the Alkaline Earths.
I attempted to combine nitrous oxide with
lime and ftrontian, by expofing fulphites of lime
and firontian with excefs of earth, to nitrous
gas ; but this procefs did not fuccced : the
diminution took place fo flovvly as to deftroy all
hopes of gaining any refults in a definite time.
Sulphite of potalh is decompofable by barytes^
ftrontian, and lime ;* confequently it was im-
poilible to employ this fubftance to efFedl the
combination*
As the dry fulphures, when well made, con-
vert nitrous gas into nitrous oxide, it is probable
that the union of the earths with nafcent nitrous
oxide may be efFeded by expofing nitrous gas
to their fulphures, containing an excefs of
earth.
Perhaps the combination of nitrous oxide with
* See the above-mentioned elaborate memoir pf Fodr-
cfoy and VauqOelin,
( 174 )
firontian may be efFe<5led by introducing the
combination ofpotafli and nitrous oxide into
Itrontian lime water.
It is probable that nitrous oxide may be com-
bined with clay and magnefia, by expofing
tbefe bodieSj mingled with fulphite of potaili
or foda, to nitrous gas.
XI. Additional Ohfervat'tons on the conihi^
nations of Nitrous Oxide with the Alkalies,
A defire to complete pbyfiological inveftiga«r
tions relating to nitrous oxide, has hitherto
prevented me from purfuing to'a greater extent,
the experiments on the combination of thisfub-
ftance with the alkalies, &c. As foon as an
opportunity occurs, I purpofe to refume the
fubjedl.
The obfervations detailed in the foregoing
fedions are fufficient to fhow that nitrous oxide
is capable of entering into intimate union with
the fixed alkalies : and as the compounds
formed by this union arc infoluble in alcohol,
( 275 )
decompofable by the acids, and heat, and pof-
fefled of peculiar properties, they ought to be
confidered as a new clafs of faline fubllances.
If it is thought proper, on a farther invefti-
gation of their properties, to fignify them by
fpecific names, they may, according to the ufu-
ally adopted fafhion of nomenclature, be called
nitroxis : thus the nitroxi of ptajh would fignify
the fait formed by the combination of nitrous
oxide with potafh.
Future experiments muft determine the
different affinities of nitrous oxide for the alka-
lies, and alkaline earths.
With regard to the ufes of thefe new com-
pounds it is difficult to form a guefs. When
they are obtained pure, and fully faturated with
nitrous oxide, on account of the low temperature
at which their gas is liberated, they will proba-
bly conftitute detonating compounds. From
their facility of decompofition by the weaker
acids, they may pofiibly be ufed medicinally, if
everthe evolution of nitrous oxide in the ftomach
ihould be found beneficial in difeafes.
( 276 )
XII. The properties of Nitrous Oxide refemhU
thofe of fields.
If we were Inclined fo generalife, and tcy
place nitrous oxide among a known clafs of
bodies, its properties would certainly induce us
to confidcr it as more analogous to the acids
than to any other fubftances ; for it is capable
of uniting with water and the alkalies, and is
infoluble in moft of the acids. It differs, how-
ever, from the flronger acids, in not poiTeffing
the four tafle/ and the power of reddening
vegetable blues : and from both the ftronger
and weaker acids, in not being combinable when
in a perfectly free flate, at common tempera-
. * The different perfons who have rcfpired nitrous oxide
have, as will be feen hereafter, given different accounts of
the tafte ; the greater number have called it fwcet, fome
metallic. One of my friends, in a letter to me dated Nov.
13, 1799, containing a detail of fome experiments made
on the refpiration of nitrous oxide, at Birmingham, denotes
the tafte of it by the term " fweetiih faintly acidulous."
To me the tafte both of the gas and of its folution in water^
has always appeared faintly fweetifli.
< 277 )
lures, with the alkalies. If it fhould be proved
by future experiments, that condenfation by
cold gave it the capability of immediately forming
neutro-faline compounds with the alkalies ; it
ought to be confidered as the weakeft of the
acids. Till thofe experiments are made^ its
extraordinary chemical and phyfiological pro-
perties are fufficient to induce us to confider i|:
as a bodyy^i generis.
It is a lingular facl that nitrous gas, which
contains in its compolltion a quantity of oxygene
fo much greater than nitrous oxide, fho^ild
neverthelefs pollefs no acid properties. It is
tincombinable with alkalies, very little foluble
in water, and abforbable by the acids.
DIVISION IL
On ibe DECOMPOSITION of NITROUS OXIDE
by COMBUSTIBLE BODIES. Its ANALYSIS.
OBSERVATIONS on the different combinations of
OXYGENE and NITROGENE,
I. Preliminaries.
Jt* ROM the phsenomena mentioned in Ref. I,
Divif. III.* it appears that the combuftible bodies
burn in nitrous oxide at certain temperatures.
The experiments in this Divifion vvereinflituted
for the purpofe of inveftigating the precife
nature of thefe combuftions, with a view of
afcertaining exadly the compofition of nitrous
oxide.
It will be feen hereafter that very high tem-
peratures are required for the decompolition of
* Seaion 2,
( 279 )
tiitraias oxide, by moll of the combuftible bodies,
and that in this proceis heat and light are pro-
duced to a very great extent. Thefe agents
alone are poflefled of a confiderable power of
adlion on nitrous oxide ; of which it is necefiary
to give an account, that we may be able to un-
derftand the phaenomena in the following
fedions.
H. Converjion of Nitrous Oxide into Nitrous
Acid^ arid a Gas analogous to Atniofpheric Aip^
by Ignition.
a. Dr. Prieflley aflerts, that nitrous oxide
expofed for a certain time to the a6lion of the
electric fpark, is rendered immifcible with
water, and capable of diminution with nitrous
gas, without fuffeiingany alteration of volume ;
and likewife that the fame changes are efteded in
it by expofure to ignited incombuftible bodies.*
The Dutch chemifts ilate, that the eledrjc
^^ Vol. ii. pag. 91.
( 280 )
fpark pafled through nitrous oxide, occafions 3^
ftnall diminution of its vohime, and that the
gas remaining is analogous to common air.-fr
They conclude that this change depends on the
reparation of its conftituent parts, oxygene and
nitrogen e, from each other.
None of thefe chemifts have fufpeded the
production of nitrous acid in this procefs.
h. Nitrous oxide undergoes no change
whatever from the fimple adlion of light. I
expofed fome of it, confined by mercury, for
many days to this agent, often paffing through
it concentrated rays by means of a fmall lens.
When examined it appeared, as well as I could
eftimate, of the fame degree of purity as at the
beginning of the experiment.
c, A temperature below that of ignition
efFe<9:s no alteration in the conftitution of
nitrous oxide. I pafled nitrous oxide from a
f Journal de Phyfique, torn, xliii, part ii. pag. 330. They
effeded the fame change by pafling it through a heated
tube. Dr. Prieftley had publifliod an account of fimilay
pperimcnts more than two years before.
{ 281 )
retort containing decompofing nitrate of am-
moniac, through a green glafs tube, flrongly
heated in an air-furnace, but not fufFered to
undergo ignition. The gas, received in a water
apparatus exhibited the fame properties as the
purcft nitrous oxide ; fomc of it abforbed by
water, left a refiduum of not quite one thir-
teenth.
d. The 2iS\on of the ele6lric fpark for a
long while continued, converts nitrous oxide
into a gas analogous tp atmofpheric air, and
nitrous acid.
I pafTed about 1 50 ftrong fhocks from a fmall
Lcyden phial, through 7 ten grain meafures of
pure nitrous oxide. After this it filled a fpace
rather lefs than fix meafures : the mercury was
rendered white on the top, as if it had been
adled on by nitric acid. Six meafures of nitrous
gas mingled with the refidual gas of the experi-
ment, over mercury covered by a little water,
gave red fumes, and rapid diminution. In five
minutes the volume of the gafes nearly equalled
t-cn. Thermometer in this experiment was 58-.
( 282 )
ElecSric fparks were pafled for an hour and half
through 7 ten grain meafures of nitrous oxide
over mercury covered with a little red cabbage
juice, previoully faturated with nitrous oxide,
and rendered green by an alkali. After the
procefs the gas filled a fpaee equal to rather
more than fix meafures and half, and the juice
was become of a pale red. The gas was intro-
duced into a fmall tube filled with pure water,
and agitated ; no abforption was perceptible :
7 meafures of nitrous gas added to it gave red
fumes, and after fix minutes a diminution to
g^ nearly. 6§ meafures of common air from
the garden, with 7 of nitrous gas, gave ex-
aflly g.
In this experiment it was evident that nitrous
oxide was converted into a gas analogous to
atmofpheric air, at the fame time that an acid
was formed. There could be little doubt but
that this was the nitrous acid. To afcertain it,
however, with greater certainty, the electric
fpark was pafTed through 6 meafures of nitrous
oxide, over a little folution of green fulphate of
( 263 )
iron, confined by mercury. As the procefs went
on, the color of the folution became rather
darker. When the diminution was com-
plete, a little pruffiate of potafh was added
to the folution. A precipitate of pale blue
pruffiate of potafli was produced.
c. Nitrous oxide was pafled from decompofing
nitrate of ammoniac, through a porcelain tube
well glazed infide and outfide, ftrongly ignited
in an air-furnace, and communicating with the
water apparatus. The gas colle(?led was ren-
dered opaque by denfe red vapor. It appeared
wholly unabforbable by water. After the pre-
cipitation of its vapor, a candle burnt in it with
nearly the fame brilliancy as in atmofpheric £lir.
20 meafures of it that had been agitated in
water immediately after its produ61ion, min-
gled with 40 meafures of nitrous gas, diminiftied
to about 47.5 ; whereas 20 meafures that had
remained unagitated for fome time after their
generation, introduced to the fame cjuafltity of
nitrous gas, gave nearly 49. 20 meafures of
atmofpheric air, with 40 of the fame nitrous gas,
were condenfed to 46.
( 284 )
The water with which the gas had been
in contadl, was ftrongly acid. A little of it
poured into a foliition of green fulphate of iron,
and then mingled with pruffian alkali, produced
a green precipitate. Hence the acid it con-
tained was evidently nitrous.
That no fource of error could have exifted
in this experiment from fiflure in the tube, I
proved, by fending water through it whilfi:
ignited, after the procefs, from the fame retort
in which the nitrate of ammoniac had been
decompofed ; a few globules of air only were
produced, not equal to one tenth of the volume
of the water boiled, and which were doubtl'efs
previoufly contained in it.
I have repeated this experiment two or three
times, with fimilar refults ; whenever the air
was agitated in water immediately after its pro-
dud ion, it gave almo/i the fame diminution with
nitrous gas as common air ; when, on the con-
trary, it has been fufFered to remain for fome time
in contadl with the phlogifticated nitrous acid
fufpended in it, the condenfation has been left
( 285 )
lrith nitrous gas by five or fix hundred parts.
Hence I am inclined to believe, that if it were
poffiblc to condenfe all the nitrous acid formed,
immediately after its generation, fo as to pre-
vent it from abforbing oxygene from the per-
rnanent gas, this gas would be found identical
with th^air of the atmofphere.
The changes efFecied by fire on nitrous
oxi-de are not analogous to thofe produced by
it in other bodies ; for the power of this agent
feems generally uniform, either in wholly fepa-
rating the conftituent principles of bodies from
each other, or in making them enter into more
intimate union. ^
It is a Angular phaenomenon, that whilfi it
candenfes one part of the oxygene and nitrogenc
of nitrous oxide, in the form of nitrous acid ;
^ On the one hand, it decompofes ammoniac into hydro-
gene and nitrogene, whilH on the other, it converts free
oxygene and nitrogene into nitrous acid. It lil^ewife con-
verts nitrous gas into nitrous acid and nitrogene. Till
we are more accurately acquainted with the nature of heat,,
light, and ele6lricity, we iliall probably be unable to ex-
plain thefe phasnomena.
( 2^6 )
it (houkl caufe the remainder to expand, in the
ftate of atmofpheric air. Does not this fa6l
afford an inference in favor of the chemical com-
pofition of atmofpheric air ?
III. Deconipofiiion of Nitrous Oxide by
Hydrogens^ at the temperature of Ignition^ , .
In the following experiments on the decom-
pofition of nitrous oxide by hydrogene, the
gafes were carefully generated in the mercurial
apparatus, and their purity afcertained by the
tefts mentioned in Refearch I. They were
meafured in fmall tubes graduated to grains,
and then transferred into the detonating tube,
which was eight tenths of an inch in diameter,
and graduated to ten grain meafures.
Thefpace occupied by the gafes being noted
after the inflammation by the eleflric fhock,
green muriate of iron, and pruffiate of potafh,
were fucceflively introduced, to afcertain if any
nitrous acid had been formed. The abforption,
if any took place, was marked> and the gafes
{ 287 )
transferred into a narrow grain meafure tube,
and their bulk and compofition accurately afcer-
tained.
b. The hydrogene employed was procured from
water by means of zinc and fulphuric acid. 50
grain meafuresofit firedby theeledlricfpark^ with
30 grain meafures of oxygene containing one
eleventh nitrogene, gave a refiduum of about 4.
Nitrous gas mingled with thofe 4, indicated the
prefence of ratherlefs than 1 of unconfumed oxy-
gene. In another experiment 23 of it, with 20 of
the fan>€oxygeneleft rather morethan6re(iduum.
The nitrous oxide was apparently pure, for
it left a remainder of about ,05 only, when ab-
forbed by common water.
c, 50 of hydrogene were fired with 40 of
nitrous oxide ; the concuffion was very great,
and the light given out bright red ; no percep-
tible quantity of nitrous acid was formed ; the
refidual gas filled a fpace equal to 52. No part
of it was abforbable by water, it gave no dimi-
nution with nitrous gas, when it was mingled
with a little oxygene, and again a6led on byihe
( 188 )
eledric fpark, an inflammation and flight dimi-
nution was produced.
J, 33 of hydrogen e were fired with 35 of
nitrous oxide : nitrous acid was produced in
very minute quantity ; the gas that remained
was not abforbable by water, and filled a fpace
equal to 37 grains. Nitrous gas mingled with
thefe, underwent a very flight diminution.
e. 46 hydrogene were fired with 46 nitrous
oxide. The quantity of nitrous acid formed
was jufl fufiicient to tinge the white prufRate
of potafh. The gafes filled a fpace equal to 49,-
gave no perceptible diminution with nitrous
gas, and did not inflame with oxygene.
./. 40 hydrogene were fired with 39 nitrous^
oxide ; no perceptible quantity of nitrous acid
was formed. The refidual gas filled a fpace
equal to 41 ; was unabforbable by water, un-
derwent no diminution when mingled with
nitrous gas ; or when acSled on by the eledric
fpark in conta6l with oxygene.
g. 20 hydrogene were fired with 64 nitrousr
oxide ; after detonation the expanfion of the^
( 289 )
gafcs was greater in this experiment than
any of the preceding ones ; denfe white
fumes were obferved in the cylinder, and
a flow contra6lion of volume took place.
After a little green muriate of iron had been
admitted, the gales filled a fpace equal to
T:^ : pruffiate of potafh mingled with the mu-
riate, gave a deeper blue than in any of the
preceding experiments. The refidual gas was
unabforbable by water: 65 of it, mingled with
65 of nitrous gas, diminifhed to 93 ; whilft 65
of common air, with 65 of nitrous gas, gave
84.
h, 8 of hydrogenc were fired with 54 of
nitrous oxide ; the fame phaenomena as were
obferved in the lafi: experiment took place ;
nitrous acid was formed ; after the abforption of
which the refidual gas filled a fpace equal to
bb, 50 of this, with an equal quantity of
nitrous gas, diminifhed to 76. In thefe pro-
ceffes the temperatures were from 56^ to 61°.
Thefe experiments are feled^ed as the moil
accurate of nearly fifty, made on the infiamma-
( 290 )
ftion of different quantities of nitrous oxide and
hydrogene.
As Mr. Keir found muriatic acid in the fluid,
produced by the inflammation of oxygene and
hydrogene in clofed vefl^els, in Dr. Priefttey*s
experiments, I preferved the refidual gas of
about 3 cubic inches of nitrous oxide, that had
been detonated at different times with lefs than
a cubic inch and half of hydrogene ; but folu-
tion of nitrate of filver was not clouded
when agitated in this gas, nor when intro-
duced into the detonating tube in which the
inflammation had been made.
From thefe experiments we learn that nitrous
oxide is decompofable at the heat of ignition,
by hydrogene, in a variety of proportions.
When the quantity of hydrogene very little
exceeds that of the nitrous oxide, both of the
gafes difappear, water is produced, no nitrous
acid is formed, and the volume of nitrogene evol-
ved is rather greater than that of the nitrous ox-
ide decompofed.
When the quantity of hydrogene is lefs than
i
( 291 )
that of the nitrous oxide, water, nitrous acid,
oxygene and nitrogene, are generated in dif-
ferent proportions ; one part of the nitrous
oxide is mofl: probably wholly decompofed by
the hydrogene, and the other part converted
into nitrous acid and atmofpheric air, in confe-
quence of the ignition.
From experiments c^ d, and e, the compofi-
tion of nitrous oxide may be deduced. In
experiment d, 39 of nitrous oxide were decom-
pofed by 40 of hydrogene, and converted into
41 of nitrogene.
Now from b it appears that 40 of hydrogene
require for their condenlation about 20.8 of
oxygene in volume ; fo that founding the efli-
mation upon the quantity of hydrogene con-
fumed, 100 parts of nitrous oxide would con-
lift nearly of 03.1 of nitrogene, and 36.9 of
oxygene. But 4] of nitrogene weigh 12.4,
Ref. T. Div. I. Confequently, deducing the com-
pofition of nitrous oxide from the quantity of
nitrogene evolved, 100 parts of it would c.onfi ft
of 63.5 nitrogene, and 36.5 oxygene.
( 202 )
Tliefe eftimations are very little differer>t
from thofe which may be deduced from the
other experim-ents, and the coincidence is in
favor of their accuracy.
From the following experiment it appears that
the temperature required for the decompofition
of nitrous oxide by hydrogcne muft be higher
than that which is neceflary to produce the in-
flammation of hydrogcne with oxygene. I in-
troduced into fmall tubes filled with equal parts
of nitrous oxide and hydrogcne, {landing on a
furface of mercury, iron wires ignited to difi^erent
degrees, from the dull red to the vivid white
heat. The gafes were always inflamed by the
white and vivid red heats ; but never by the
dull red heat, though the laft uniformly inflamed
mixtures of oxygene and hydrogcne, and at-
niofpheric air and hydrogcne.
Dr. Prieftley * firft detonated together nitrous
oxide and hydrogcne ; his experiment was
repeated by the Dutch chemifts, who found
that when a fmall quantity of hydrogcne was
*Vol. ii, pag. 83.
( 293 )
smployed, the nitrous oxide was partially con-
verted into a gas analogous to common air.
Their eftimation of its compofition, which is
not far removed from the truth, was founded
on this phaenomenon.^
IV. Decompojition of Nitrous Oxide by Phof-
phorus.
a. Phofphorus introduced into pure nitrous
oxide at common temperatures, is not at all
luminous. It is capable of being fufed, and
even fublimed in it, without undergoing acidifi-
cation, and without effefling any alteration in
itscompofition.
About 2 grains of phofphorus were fufed, and
gradually fublimed, in 2 cubic inches of pure
nitrous oxide, over mercury, by the heat of a
* Journal de Phylique, torn, xliii. part 2, pag. 331.
They fuppofed it to confift of about 37,5 oxygene, and
62,5 nitrogene. The nearnefs of this account to the truth
is iingular, when we confider that they were neither ac-
quainted with the fpecific gravity of nitrous oxide, nor
with the production of nitrous acid in this experiment.
( ^9^ )
burning lens. No alteration was produced in
the volume of gas, and a portion of it abforbed
by water, left a reliduum of one tyvelfth only.
Phofphorus was fublimed in pure nitrous
oxide over mercury, in a dark room, by an
iron heated nearly to ignition ; but no luminous
appearance was perceptible, nor was any gas
decompofed.
b. Phofphorus decompofes nitrous oxide at
the temperature of ignition, with greater or lefs
rapidity, according to the degree of heat. We
have already feen, that when phofphorus in aflive
inflammation is introduced into nitrous oxide, it
burns with intenfely vivid light.
Phofphorus was fublimed by a heated wire in
ajar filled with nitrous oxide, {landing over warm
mercury. In this ftate of fublimation an iron
heated dull red was introduced to it by being
rapidly paflied through the mercury ; a light
blue flanie furrounded the wire, and difappeared
as foon as it ceafed to be red.
To phofphorus fublimed as before, in nitrous
oxide, over warm mercury, a thick wire ignited
( 295 )
to whltenefs was introduced ; a terrible detona-
tion took place, and the jar was fhattered in
pieces.
By employing thick conical jars,* containing
only a fmall quantity of nitrous oxide, I efFedled
the detonation feveral times with fafety ; but
on account of the great expanfion of the elaftio
produ6ls, the jar was generally either raifed
from the mercury, or portions of gas were
thrown out of it. Hence I was unable to afcer-
tain the exatft changes produced by this mode
of decompofition.
c. As my firft attempts to afcertain the confti-
tution of nitrous oxide were made on its decom-
pofition by phofphorus, I employed many dif-
* Experiments on the detonatio.u of nitrous oxide with
phofphorus in this way require great attention. The deto-
nating jar fhould be very conical 3 the nitrous oxide em-
ployed fhould never equal more than one eighth of the
capacity of the jar. The wire for the inflammation muft
be very thick, and curved fo as to be ealily introduced into
the jar. When ignited, it muft be inflantaneoufly pafled
through the heated mercury into the jar.
Perhaps the eledric fpark might be advantageoully ap-
plied for detonating phofphoric vapor with nitrous oxide.
(296)
fcrent modes of partially igniting this Aibftance
in it over mercury, fo as to produce a com-
buftion without explofion.
The firft method adopted was inflammation
by means of oxygenated muriate of potafh. A
fmall particle of oxygenated muriate of potafli
was infcrted into the phofphorus to be burnt.
On the application of a wire, moderately hot,
to the point of infertion, the fait was decom-
pofed by the phofphorus, and lufficient fire
generated and partially applied by the flight
explofion, to produce the combuftion of the
phofphorus, without the previous fublimation
of any part of it.
The fecond way employed was the ignition
of a part of the phofphorus, by means of the
combuftion of a fmall portion of tinder of cot-
ton,* or paper, in contadl with it, by the
burning glafs.
The third, and moft fuccefsful mode, was
by introducing into the graduated jar containing
* It will be feen hereafter that thefe bodies are eafily
inflamed in nitrous oxide*
( ^97 )
the nitrous oxide, the phofphorus in a fmall
tube containing oxygene, fo balanced as to
fwim on the lurface of the mercury, without
communicating with the nitrous oxide. The
phofphorus was fired in the oxygene with an
ignited iron wire, by which at the moment of
combuftion, the tube containing it was raifed
into the nitrous oxide, and thus the inflamma-
tion continued.
d. In different experiments, made with accu-
racyjifoundthatthewholeofaquantity of nitrous
oxide was never decompofable by ignited phof-
phorus ; the combuftion always flopped when
the nitrous oxide remaining was to the nitro-
gene evolved as about 1 to 5 ; likewife that the
volume of nitrogene produced was rather lefs
than that of the nitrous oxide decompofed, and
that this deficiency arofe from the formation of
nitrous acid by the intenfe ignition produced
during the procefs.
Of one experiment I fhall give a detail.
Temperature being 48°, two cubic inches
of pure nitrous oxide, which had been generated
( 298 >
over mercury, were introduced into ajar of the
capacity of 9 cubic inches, graduated to,l cubic
inches, and much enlarged at the bafe. A grain
of phofphorus was inferted into a fmall veflel
about one third of an inch long, and half an
inch in diameter, containing about 15 grain
xneafures of very pure oxygene ; this veflel,
which fwam on the furface of the mercury, was
carefully introduced into the jar containing thq
nitrous oxide. The phofphorus was fired by
means of a heated wire, and before the oxygene
was wholly confumed, the vefTel containing it
elevated into the nitrous oxide. The com-
buftion was extremely vivid and rapid. After
the atmofpheric temperature was reftored, the
gas was rendered opaque by denfe white vapor.
When this had been precipitated, and the fmall
vefTel removed from the jar, the gas filled a
fpace nearly equal to l.Q cubic inches. On
introducing to it a little folution of green mu-
riate of iron, and pruffiate of potafh, green
pruffiate of iron was produced : hence, evi-
dently, nitrous acid had been formed.
( 299 )
On the admiffion of pure water, an abforp-
tion of rather more than ,3 took place.
The 16 meafures reniaining underwent no
perceptible diminution with nitrous gas ; the
taper plunged into them was inftantly extin-
guifhed.
To afcertain if the phofphoric acid produced
in the experiments made under mercury did
not in fome meafure prevent the decompofition
of the whole of the nitrous oxide by the phof-
phorus, I introduced into a mixture of 5 nitro-
gene and 1 nitrous oxide, ignited phofphorus :
but it was immediately extingui(hed.*
The Dutch Chemifts found that phofphorus
might be fufed in nitrous oxide without being
luminous. They aflert that phofphorus in a
Hate of inflammation, introduced into this gas,
was immediately extinguifhed ; though when
taken out into the atmofphere, it again burnt
of its own accord.-f- It is difficult to account
for their miftake.
* Phofphorus burnt feebly with a white flame in a iiiix*
ture of 4 nitrogene and 1 nitrous oxide.
t Journal de Phyfique, xliii. 328,
( 300 )
V, Decompofition of Nitrons Oxide hy Flof-
phorated Hydrogene,
a. It has been mentioned in Ref. II. Div. I.
that phofphorated hydrogene and nitrous oxide
pofTefs no aflion on each other, at atmofpheric
temperatures.
Phofphorated hydrogene mingled with ni-
trous oxide, is capable of being inflamed by the
eledlric fpark, or by ignition.
h.E, 1. 10 grain meafures of phofphorated hy-
drogene, carefully produced by means of phofpho-
rus and folution of cauftic alkali, were mingled
with 52 meafures of nitrous oxide. The eledlric
fpark pafled through them, produced a vivid
inflammation. The elaftic produdls were
clouded with denfe white vapor, and after fome
minutes filled a fpace nearly equal to 6o. On
the introdudlion of water, no abforption took
place. When 43 of nitrous gas were admitted,
the whole diminifhed to 70.
jE. 2. 25 of nitrous oxide were fired with 10
( 301 >
of phofphorated hydrogene, by the ele6\ric
fpark. After detonation=^ they filled a fpace
exadlly equal to 25. On the admiffion of
Solution of green fulphate of iron, and pruffiate
of potafli, no blue or green precipitate was pro-
duced. On the introdudlion of water, no dimi-
nution was perceived.- 25 of nitrous gas ming-
led with them, gave exadlly 50.
JS. 3. 10 of nitrous oxide, mingled with 20 of
phofphorated hydrogene, could not be inflamed.
25 of nitrous oxide, with 20 phofphorated
hydrogene, inflamed. The gas afler detonation,
was rendered opaque by denfe white vapor, and
filled a fpace nearly equal to 45. No abforption
took place when water was introduced. On
admitting a little oxygene no white fumes, or
diminution, was perceived. The eledlric fpark
paflfed through the mixture, produced an ex*,
plofion, with great diminution.
c. From E. 1 it appears, that when a fmall quan-
tity of phofphorated hydrogene is inflamed with
* In this experiment, as in the laft, denfe white vapor
was produced.
( 302 )
nitrous oxide, both the phofphorus and hydro-
gene are confumed ; wbilft the fuperabundant
nitrous oxide, is converted into nitrous acid and
atmofpheric air, by the ignition ; or a certain
quantity is partially decompofed into atmofpheric
airby the combination of a portion of its oxygene
with the combuflible gas.
From E.Qj we learn, that when the phofphorated
hydrogene and nitrous oxide are to each other
as 25 to JO nearly, they both difappear, whilft
nitrogene is evolved, and water and phofphoric
acid produced. Reafoning concerning the
compofition of nitrous oxide from this experi-
ment, we fhould conclude that it was compofed
of about 38 oxygene, and 62 nitrogene.
The refult of £. 3 is interefting ; we are taught
from it that the affinity of phofphorus for the
oxygene of nitrous oxide is ilronger than that
of hydrogene, at the temperature of ignition ;
fo that when phofphorated hydrogene is min-
gled with a quantity of nitrous oxide, not con-
taining fufficient oxygene to burn both its con-
flituent parts, the phofphorus only is confumed,
whilft the hydrogene is liberated.
( 30*3 )
In repeating the experiments with phofpho-
rated hydrogene that had remained for fome
hours in the mercurial apparatus^ I did not gain
cxadly the fame refults ; for a larger quantity
of it was required to decompofe the nitrous
oxide, than in the former experiments ; doubt-
lefs from its having depofited a portion of its
phofphorus. They confirm, however, the
above mentioned conclulions.
In the courfe of experimenting, I pafled the
elecSlric fpark, for a quarter of an hour, through
about 60 meafures of phofphorated hydrogene.
It underwent no alteration of volume. Phof-
phorus was apparently precipitated from it, and
it ihad wholly loft its power of inflaming, in
contadl with common air.
VI. Decompojition of Nitrous Oxide by Sul*
fhur.
From the phasnomena before mentioned,*
* Ref. I. Div. III. S. II.
( 304 )
relating to the combuftion of fulphur in nitrous
oxide, it was evident that this gas was only de-
compofable by it, at a much higher temperature
than common air.
I introduced into fulphur in contadl with
nitrous oxide, over mercury heated to ] 12® —
114°, a wire intenfely ignited. It loft much
of its heat in paffing through the mercury, but
ftill appeared red in the vefTel. The fulphur
rapidly fufed, and fublimed without being at
all luminous. This experiment was repeated
five or fix times, but in no inftance could the
combuftion of fulphur, by means of the ignited
wire, be cff^edled.
I inflamed fulphur in nitrous oxide in the
fame manner as phofphorus ; namely, by intro-
ducing it into the fmall vefTel filled with oxy-
gene, and igniting it by means of the heated
wire. In thefe experiments the fulphur burnt
with a vivid rofe-colored light, and much ful-
phuric, with a little fulphureous acid, was formed.
Experimenting in this way I was never, how-
ever, able to decompofe more than one third
( 305 )
of the quantity of nitrous oxide employed;
not only the nitrogene evolved, but likewife the
fulphuric and fulphureous acids produced^ flop-
ping the combuftion.
I found that fulphur in a Hate of vivid in-
flammation, when introduced into a mixture of
one fourth nitrogene, and three fourths nitrous
oxide, burnt with a flame very much enlarged,
and of a vivid rofe color. In one third nitro-
gene, and two thirds nitrous oxide, it burnt
feebly with a yellow flame. In equal parts of
nitrous oxide and nitrogene, it was inftantly
extinguiflied.
Sulphur burnt feebly, with a light yellow
flame, when introduced ignited into a mixture
of 5 nitrous gas, and 6 nitrous oxide. In one
third nitrous oxide, and two thirds nitrous gas,
it was inftantly extinguiflied. From many
circumftances, I am inclined to believe that ful-
phur is incapable, at any temperature, of flowly
decompofing nitrous oxide, fo as tp burn in it
with a blue flame, forming fulphureous acid
alone. It appears to attradt oxyg^ne from it
u
( 306 )
only when intenfely ignited, fo as to form
chiefly fulphuiic acid, and that with great
rapidity, and vivid inflammation.
VII. Decompqfition of Nitrous Oxide hy Szd-
phurated Hydrogene.
a. Though nitrous oxide and fulphurated
hydrogene do not adl upoii each other at com-
mon temperatures, yet they undergo a mutual
decompofition when mingled together in certain
proportions, and ignited by the elediric fpark.
From more than twenty experiments made
on the inflammation of fulphurated hydrogene
in nitrous oxide, I fele6l the following as the
moft conclufivc and accurate. The temperature
at which they were made was from 4P to 49°.
I. E, \, About 35 meafures of nitrous
oxide were fired with 10 of fulphurated hydro-
gene ; the expanfion during inflammation was
very great, and the flame flcy-blue. Imme-
diately after, the gafes filled a fpace equal to
48 nearly. White fumes were then formed,
and they gradually contrac5led to 40. On the
( 307 )
admiffion of a little flrontian lime water, a flight
abforption took place, with white precipitation ;
and the volunne occupied by tlie refidual gas
nearly equalled 37- On admitting nitrous gas
to thefe^ no perceptible diminution took place.
E. 2. 20 fulphurated hydrogene, with 25
nitrous oxide, could not be inflamed.
30 nitrous oxide, with 22 fulphurated hydro-
gene, could not be inflamed.
35 nitrous oxide, with 20 fulphurated hydro-
gene, inflamed with vivid blue light, and great
expanfion. After the explofion, the g^fes filled
exadly the fame fpace as before the experiment;
no white fumes were perceived, and no farther
contradion occurred. On the addition of
llrontian lime water, a copious precipitation,
with diminution, took place ; and the refldual
gas filled a fpace nearly equal to 35^.
E. 3. 47 nitrous oxide, and 14 fulphurated
hydrogene, inflamed. After the explofion, the
gafes filled a fpace nearly equal to 65 ; then white
fumes formed, and they gradually diminiflied
to 52. On the introdu<5lion of muriate of ftron-
( 308 )
tian, a copious white precipitate was produced' ;
and on the addition of water, no further ab-
forption took place. To the refidual 52, about
20 of nitrous gas were added ; they filled toge-
ther a fpace equal to about 67.
c. In none of the experiments made on the
inflammation of fulphurated hydrogene and
nitrous oxide, could I afcertain with certainty
the precipitation of fulphur. In one or two
proceiTes the detonating tube wSs rendered a
little white at the points of contaft with the
mercury ; but this was moft probably owing to
the oxydation of the mercury, either by the
heated fulphuric acid formed, or from nitrous
acid produced by the ignition* The prefence
of nitrous acid I could not afcertain in thefe pro-
cefles by my ufual tefts, becaufe the combuftion
of fulphur over white pruffiate of iron, converts
it into light green.
When I introduced an inflamed taper into
about 3 parts of fulphurated hydrogene, and 2
parts of nitrous oxide, in which proportions
they could not have been fired by th«
( 309 )
dedlric fpark, a blue flame pafled through them,
and much fulphur was depofitcd on the fides of
the vefiel. But this fulphur moft probably owed
its formation to the decompofition of a portion of
fulphurated hydrogene not burnt, by the ful-
phureous acid formed from the combuftion of
the other portion.
We may then conclude with probability, that
fulphurated hydrogene and nitrous oxide will not
decompbfe each other, when a6led on by the elec-
tric fpark, unlefs their proportions are fuch as to
enable the whole of the fulphurated hydrogene
to be decompofed, fo that both of its conftituents
may become oxygenated, by attracting oxygene
from the nitrous oxide : likewife, that when the
fulphurated hydrogene is at its maximum
of inflammation, the hydrogene and fulphur
form with the whole of the oxygene of nitrous
oxide, water and fulphureous acid ; E,2: whercr-
as at its minimum they produce water, and
c]\\Qfiy, perhaps wholly, fulphuric acid ; at the
fame time that the nitrous oxide partially de-
compofed, is converted into nitrogene, and 3
( 310)
gas analogous to atmofpheric air, or into nitro-
gene, nitrous acid, and atmofpheric air. E, 1.
E. 3.
By purfuing thofe experiments, and ufing larger
Quantities of gas, we may probably be able to
afcertain from them with accuracy, the com-
pofition of fulphuric and fulphureous acids.
I own I was difappointed in the refults, for I
expelled to have been able to afcertain from
ihem, the relative affinities of fulphur, and
hydrogene for the oxygene of nitrous oxide,
at the temperature of ignition. I conjedlured
that nitrous oxide, mingled with excefs of ful-
phurated hydrogene, would have been decom-
pofed, and one of the principles of it evolved
unaltered, as was the cafe with phofphorated
hydrogene.
If we eftimate the compofition of nitrous
oxide from the quantity of nitrogene produced in
E. 2, it is compofed of about 6l nitrogene, and
*39 oxygene.
( 311 )
VIII. Decompofttion of Nitrous Oxide Ij
Charcoal,
An account of the analyfis of nitrous oxide
by charcoal is given in Ref. I. Div. III. 1 have
lately made two experiments on thecombuftion
of charcoal in nitrous oxide, in which every
precaution was taken to prevent the exiflence of
fources of error. Of one of thefe I Ihall give
a detail.
Eji Temperature being 5 1°^ about a grain of
charcoal, which had been expofed for fome
hours to a red heat, was introduced whilft
ignited, under mercury, and transferred into a
graduated jar, containing 3 cubic inches of pure
nitrous oxide, ftanding over dry mercury.
The focus of a burning lens was thrown on
the charcoal ; it inflantly inflamed, and burnt
with great vividnefs for near a minute, the gas
being much expanded. The focus was con-
tinually applied to it for ten minutes, when the
procefs appeared at an end. The gafes, when
the common temperature and prefTure were
( 312 )
reftored, filled a fpace equal to 4/2 cubic
inches.
On introducing into them a few grain mea-
fures of folution of green muriate of iron, for
the double purpofe of faturating them with
moifture, and afcertaining if any nitrous acid
had been formed, no change of volume took
place ; and pruffiate of potafh gave with the
muriate a white precipitate only.
On the admiffion of a fmall quantity of con-
centrated folution of cauftic potafh, a diminu-
tion of the gas Hovvly took place ; when it was
complete the volume equalled about 3.05 cubic
inches. By agitation in well boiled water,
about ,9 of thefe were abforbed ; the remainder
appeared to be pure nitrogene.
The difference between the eflimation founded
upon the nitrogene evolved, and that deduced
from the carbonic acid generated in this experi-
ment, is not nearly fo great as in that Ref. I.
Div. III. Taking about the mean proportions,
we fhould conclude that nitrous oxide wascom-
pofed of about 38 oxygene, and 62 nitrogene.
( 313 )
Charcoal burnt with greater vivldnefs than in
common air, in a mixture of one third nitrogene
and two thirds nitrous oxide. In equal parts of
nitrous oxide and nitrogene, its light was barely
perceptible. In one third nitrous oxide, and
two thirds nitrogene, it was almoft imm,ediately
extinguiflied.
As charcoal burns vividly in nitrous gas,
when it has been previoufly ignited to white-
nefs, I introduced it into a mixture of equal
parts of nitrous oxide and nitrous gas ; it burnt
with a deep and bright red.
IX. Decompojition of Nitrous Oxide hy
Vo-carhonate,
Nitrous oxide, and hydro-carbonate, pofTefs
no action on each other, except at high tem-
peratures. When mingled in certain propor-
tions, and expofed to the eledlric (hock, a new
arrangement of their principles takes place.
E. 1. Temperature being 53^, 35 of
nitrous oxide, mingled with 15 of hydro-
(314)
carbonate, were fired by the electric Ipark ;
the inflammation was very vivid, and the
light produced, bright red. After the
exploflon, the fpace occupied by the gafes
equalled about 6o. On the admiflion of folu-
tion of ftrontian, a copious white precipitate
was produced, and the gas diminifhed by agita-
tion, to rather moi:e than 35. When 36 of
nitrous gas were added to thefe, white fumes
appeared and the whole diminifhed to 62.
When a little muriatic acid was poured on the
w^hite precipitate from the folution of ftrontian,
gas was evolved from it, and it was gradually
diflblved.
E, 2. 22 nitrous oxide were inflamed with
20 hydro-carbonate ; after the explofion, they
filled a fpace equal to 45 ; when ftrontian lime
water was introducied, white precipitation took
place, and the diminution was to 31.
To thefe 31, 14 of nitrous oxide were ad-
mitted, and the electric fpark pafled through
them ; an inflammation took place : carbonic
acid was 'formed, after the abforption of which,
( 315 )
the gas remaining filled a fpace equal to 43, and
did not diminifh with nitrous gas.
The hydro- carbonate employed in thefe ex-
periments, was procured from alcohol by me^ns
of fulphuric acid. In another fet of experi-
ments made with lefs accuracy, the fame general
refults were obtained. Whenever hydro-car-
bonate inflamed with nitrous oxide, both its
conllituents were oxygenated ; in all cafes car-
bonic acid was formed, and in no inftance free
hydrogene evolved, or charcoal precipitated.
In the decornpofition of nitrous oxide by hy-
dro-carbonate, the refidual nitrogenc is lefs
than in in other combuftions. This circura-
ftance I am unable to explain.
Reafoning from analogy, there can be little
doubt, but that when hydro-carbonate is in-
flamed with excefs of nitrous oxide, it will be
only partially decompounded, or converted into
nitrogenc, nitrous acid, and atmofpheric air.
The Dutch Chemifts have aflerted, that char-
coal does not burn in nitrous oxide, except in
confequence of the previous decornpofition of
HiiMI
. (316)
the gas by the hydrogenealways contained in this
fubftance ; and likewife, that when hydro-car-
bonate and nitrous oxide were mingled together,
and fired by the eleflric fpark, the hydrogene only
was burnt, whilfl the charcoal was precipitated.
It is difficult to account for thefe numerous
miftakes. Their theory of the non-refpir ability
of nitrous oxide was founded upon them. They
fuppofed that the chief ufe of refpiration was
to deprive the blood of its fuperabundant car-
bon, by the combination of atmofpheric oxy-
gene with that principle; and that nitrous oxide
was highly fatal to life, becaufe it was incapable
of de-carbonatingthe blood^ ! !
X. Combujiion of Iron in Nitrous . Oxide.
I introduced into ajar of tlje capacity of 20
cubic inches, containing 11 cubic inches of
nitrous oxide, over mercury, a fmall quantity
of fine iron wire twifted together, and having
* Journal dc Phylique^ xliii. 334..
(317 )
affixed to it a particle of cork. On throwing
the focus of a burning glafs on the corkf it
inftantly inflamed, and the fire was communi-
cated to the wire, which burnt with great
vividnefs for feme moments, projedling bril-
liant white fparks. After it had ceafed to burn
the gas was increafed in volume rather more
than three tenths of an inch. The nitrous acid
tefts were introduced, but no acid appeared to
have been formed. On expofing the gas to
water, near 4,*2 cubic inches were abforbed : the
7,1 remaining appeared to be pure nitrogene.
From this experiment it is evident that iron
at the temperature of ignition, is capable of
decompoiing nitrous oxide ; likewife that it is
incapable of burning in it when it contains more
than three fifths nitrogene.
. I attempted to inflame zinc in nitrous oxide,
in the fame way as iron ; but without fuccefs.
By keeping the focus of a burning glafs upon
fome zinc filings, in a fmall quantity of nitrous
oxide, I converted a little of the zinc into white
oxide, and confequently decompofed a portion
of the gas.
f SIS ^
XL C-mr^^fim tf fy wfiw u m 2^Mrmu
VpopkformB^ vUdi infttmcs ia aitroos g»»
Jjfrfi^Jiriir 3Br, at cm* dca bdov .«0»; re-
far to €onimSkm ia okroos onde a
■c^ MrIicj toapcntivc. It wfll not bora io
, or alter k, cvca ai %11^.
Ihaico&s inflMinil pfrapbonsia utraos
r, b^ mcansof a wire fipQ^j
batMCigvtod. Tbe %fat pradnccd
% tkc iftMUDa €£ fyropboffiB ia oitroas oside
is viiitCy &c liiai fodTfri by it io oi. jgeoe :
ia aitHMSgas it s redL
Wbca lyropQoriK baims oat in ailroyi cttkfa^
a Etdc iaoofe of tbe FoliBBe of gasis pn
agitated in
; bat Ae 4|aagtitj ctf" iraiboair acid
is cxticBBeiy OHnaie. I bxvc utxar
aifymfbarasm aitmaiandc.
(319)
XII. Combujiion of the Taper m Nitrous
Oxide,
It has been noticed by different experi-
mentalifts, that the taper burns with a flame
conliderably enlarged in nitrous oxide : fome-
times with a vivid light and crackling noife, as
in oxygene ; at other times with a white central
flame, furrounded by a feeble blue one.
My experiments on the combuftlon of the
taper in nitrous oxide, were chiefly made with
a view to afcertain the caufe of the double
flame.
When the inflamed taper is introduced into
pure nitrous oxide, it burns at firfi: with a bril-
liant white light, and fparkles as in oxygene.
As the combuflion goes on, the brilliancy of the
flame diminiflies ; it gradually lengthens, and
becomes furrounded with a pale blue cone of
light, from the apex of which nviich unburnt
charcoal is thrown off", in the fonii of fmoke.
The flame continues double to the end of the
procefs.
( 320 )
When the refidual gafes are examined after
combuftion, much nitrous acid is found fuf-
pended in them ; and they are compofed of
carbonic acid, nitrogene, and about one fourth
of undecompounded nitrous oxide.
The double flame depends upon the nitrous
acid formed by the ignition ; for it can be pro-
duced by plunging the taper into common air
containing nitrous acid vapor, or into a mix-
ture of nitrous oxide and nitrogene, through
which nitrous acid has been difFufed. It is
never perceived in the combuftion of the taper,
till much riitrous acid is formed.
In attempting to refpire fome reiidual gas of
nitrous oxide, in which a taper had burnt out, I
found it fo highly impregnated with nitrous acid,
as to difable me from even taking it into my
mouth.
The taper burns in a mixture of equal parts
nitrous oxide and nitrogene, at firfl with a
flame nearly the fame as that of a candle in
common air ; white. Before its extindion the
interior white flame, and exterior blue flame,
are perceived.
( 321 )
The taper is inftantly extinguifhed in a mix-
ture of one fourth nitrous oxide, and three
fourths nitrogene.
In a mixture of equal parts nitrous oxide and
nitrous gas, the taper burns at firft with nearly
as much brilliancy as in pure nitrous oxide 5
gradually the double and feeble flame is pro-
duced.
XI 11. On the Combuftion of different Com-
pound Bodies in Nitrous Oxide.
All the folid and fluid compound inflammable
bodies on which I have experimented, burn in
nitrous oxide, at high temperatures. Wood, cot-
ton, and paper, are eafily inflamed in it by the
burning glafs. During their combuftion, ni-
trous acid is always formed, carbonic acid, and
water produced, and nitrogene evolved, rather
lefs in bulk than the nitrous oxide decompofed.
I have already mentioned that alcohol and
ether are foluble in nitrous oxide.. When an
ignited body is introduced into the folution of
w
( 3^2 )
alcohol, or ether in nitrous oxide, a flight
exploflon takes place.
XIV. General Coriclufions relating to the
Decompofiiion of Nitrons Oxtde^ arid to its
Analyfis.
From what has been faid in the preceding
feciions, it appears that the inflammable bodies,
in general, require for their combuflion m
nitrous oxide, much higher temperatures thaa
thofe at which they burn in atmolpheric air^ or
oxygene.
When intenfely heated they decompofe it,
with the prcdudion of much heat and light,
and become oxygenated.
During the combuflion of folid or fluid bodies,
producing flame, in nitrous oxide, nitrous acid
is generated, mofl probably from a new arrange-
ment of principles, analogous to thofe obferved
in Sed. II, by the ignition of that part of the
gas not in conta6l with the burning fubflance.
Likewife when nitrous oxide in excefs is decom-
( 323 )
pofed by inflammable gafes, nitrous acid, and
Ibmetimes a gas analogous to common air, is
produced, doubtlefs from the fame caufe.
Pyrophorus is the only body that inflames in
nitrous oxide, below the temperature of
ignition.
Phofphorus burns in it with the blufe flame,
probably forming with its oxygene only phof-
phoreous acid at the dull red heat, and with the
intenfely vivid flame, producing phofphoric acid
at the white heat.
Hydrogene, charcoal, fulphur, iron, and the
compound inflammable bodies, decompofe it
only at heats equal to, or above, that of ignition s
probably each a different temperature.
From the phs&nomena in Se6l. V. it appears,
that at the temperature of intenfe ignition, phof-
phorus has a flronger affinity for the oxygene
of nitrous oxide than hydrogene ; and reafoning
from the different degrees of combuftibility of
the inflammable bodies, in mixtures of nitrous
oxide and nitrogene, and from other phaeno-
( 324 )
mena, we may conclude with probability, that
at about the white heat, the affinity of the com--
buftible bodies for oxygene takes place in the
following order. Phofphorus^ hydrogene, char-
coal,* iron, fulphur, &c.
This order of attradlion is very difFererat
from that obtaining at the red beat ; in
which temperature charcoal and iron have a;
nmch ftronger affinity for oxygene than either
phofphorus or hydrogene.-^
The fmalleft quantity of oxygene given in
the different analyfes of nitrous oxide juft de-
tailed, is thirty five hundred parts ; the greateft
proportion is thirty-nine.
Taking the mean eftimations from the mod
accurate experiments, we may conclude that
100 grains of the known ponderable matter of
* As is proved by the decompofition of oxide of iron artd
fulphuric acid by charcoal, at that temperature,
f Hydrogenc at or about the red heat, appears to attraA
oxygene ftronger than phofphorus. See Dr. Prieftley's
experiments, vol. i. page 262.
( 325 )
nitrous oxide, confi ft of about 3 6, 7 oxygen e,
and 63,3 nitrogene ; or taking away decimals,
of 37 oxygeneto63nitroggie; which is identical
with the eftimation given in Refearcb I.
XV. Obfervations on the combinations of
Oxygene . and Nitrogene.
During tlie decompofitions of the combina-
tions of oxygene and nitrogene by combuftible
bodies, a confiderable momentary expanfion of
the adling fubftances, ^nd the bodies in contadl
with them is generally produced, connedled with
increafed temperature ; whilft light is often
generated to a great extent.
Of the caufes ofthefe phasnomena we are at
prefent ignorant. Our knowledge of them
muft depend upon the difcovery of the precife
nature of heat and light, and of the laws by
which they are governed. The application of
general hypothefes to ifolated fa61s can be of
little utility ; for this reafon I fhall at prefent
forbear to enter into any difcuffions concerning
( 326 )
thofe agents, which are imperceptible to the
fenfes, and known only by folitary cfFedls.
Analyfis and fynthefis clearly prove that
oxygene and nitrogene conftitute the known
ponderable matter of atmofpheric air, nitrous
oxide, nitrous gas, and nitric acid.
That the oxygene and nitrogene of atmof-
pheric air exift in chemical union, appears
almoft demonftrable from the following evi-
dences.
ift. The equable difFufion of oxygene and
nitrogene through every part of the atmofphere,
which can hardly be fuppofed to depend on
any other caufe than an affinity between thefe
principles.*
2dly. The difference between the fpecific
* That attradion muft be called chemical, which enables
bodies of different fpecific gavities to unite in fuch a manner
as to produce a compound, in every part of which the con-
flituents are found in the fame proportions to each other.
Atmofpheric air, examined after having been at perfe6t
reft in clofed vefTels, for a great length of time, contains in
every part the fame proportions of oxygene and nitrogene;
whereas if no affinity exifted between thefe principles,
following the laws of fpecific gravity, they ought to fe^a^
( 327 )
gravity of atmofpberic air, and a mixture of 27
parts oxygene and 73 nitrogene, as found by
calculation ; a difference apparently owing to
expanlion in confequence of combination.
3dly. The converfion of nitrous oxide into
nitrous acid, and a gas analogous to common
air, by ignition.
4thly. The folubility of atmofpheric air un-
decom pounded in water.
Atmospheric Air, then, may be confi-
dered as the leaft intimate of the combinations
of nitrogcne and oxygene.
It is an elaftic fluid, permanent at all known
temperatures, confifting of ,73 nitrogene, and
,27 oxygene. It is decompofable at certain tem-
peratures, by moft of the bodies poflefling
affinity for oxygene. It is foluble in about
thirty times its bulk of water, and as far as we
are acquainted with its affinities, incapable of
rate 5 the oxygene forming the inferior, the nitrogene the
fnperior ftratum.
The fuppolition of the chemical compofition of atmof-
pheric air, has been advanced by many philofophers. The
two firft evidences have been often noticed.
( 328 )
combining with mofl of the fimple and com-
pound fubftances. 100 cubic inches of it
weigh about 31 grains at 55° temperature, and
30 atmofpheric preflTure.
Nitrous Oxide is a gas unalterable in its
conftitution, at temperatures below ignition.
It is compofed of oxygene and nitrogene, exift-
ing perhaps in the moft intimate union which
thofe fubftances are capable of afTuming.*
Its properties approach to thofe of acids. It
is decompofable by the combuftible bodies at
very high temperatures, is foluble in double its
volume of water, and in half its bulk of moft of
the inflammable fluids. It is combinable with
the alkalies, and capable of forming with them
peculiar falts. 100 grains of it are compofed
of about 63 nitrogene, and 37 oxygene.
100 cubic inches of it weigh 50 grains,
at 55° temperature, and 30 atmofpheric pref-
fure.
* For it is unalterable by thofe bodies wliich are capable
of attracting oxygene from nitrous gas and nitrous acid, at
common temperatures.
(329)
Nitrous Gas is compofed of about ,56
oxygene, and ,44 nitrogene, in intimate union.
It is foluble in twelve times its bulk of vvater,_
and is combinable with the acids, and certain
metallic folutions ; it is poilefled of no acid
properties, and is decompofable by moft of the
bodies that attraft oxygene ftrongly, at high
temperatures. 100 cubic inches of it weigh
about 34 grains, at the mean temperature and
prefTure.
Nitric Acid is a fubflance permanently
aeriform at common temperatures, compofed of
about 1 nitrogene, to 2,3 oxygene. It is folu-
ble to a great extent in water, and combinable
with the alkalies, and nitrous gas. It is decom-
pofable by moft of the combuftible bodies, at
certain temperatures. 100 cubic inches of it
weigh, at the mean temperature and prefTure,
nearly 76 grains.
RESEARCH III.
BELATING TO THE RESPIRATION OF
I^ITROUS OXIDE,
AND OTHER
GASES.
RESEARCH HI.
DIVISION I.
EXPERIMENTS and OBSERVATIONS on the
EFFECTS produced upon ANIMALS by the RES-
PIRATION of NITROUS OXIDE.
I. Preliminaries,
J. HE term re/prab/e, in its phyfiological
application, has been differently employed. Some
times by the refpirability of a gas has been
meant, its power of fupporting life for a great
length of time, when repeatedly applied to the
blood in the lungs. At other times all gafes
have been confidered as refpirable, which were
capable of introduction into the lungs by volun-
tary efforts, without any relation to their
vitality.
( 334 )
In the lafl fenfe the word refpirable is moft
properly employed. In this fenfe it is ufed in
the following fedlions.
Non-refpirable gafes are thofe, which when
applied to the external organs of refpiration^
ftimulate the mufcles of the epiglottis in fuch a
way as to keep it perfectly clofe on the glottis ;
thus preventing the fmalleft particle of gas from
entering into the bronchia, in fpite of voluntary
exertions ; fuch are carbonic acid, and acid gafes
in general.*
Of refpirable gafes, or thofe which are capa-
ble of being taken into the lungs by voluntary
efforts.
One only has the power of uniformly fup-
porting life ; — atmofpheric air. Other gafes,
when refpired, fooner or later produce death ;
but in different modes.
Some, as nitrogene and hydrogene, efFedl no
pofitive change in the venous blood. Animals
* See the curious experiments of Roficr, Journal dc
Phyfique, 17Q6, vol. 1, pag. 419-
( 335 )
immerfed in thefe gafes die of a difeafe pro-
duced by privation of atmofpheric air, analogous
to that occafioned by their fubmerfion in water,
or non-refpirable gafes.
Others, as the different varieties of hydro-
carbonate, deftroy life by producing fome pofi-
tive change=^ in the blood, which probably im-
mediately renders it incapable of fupplying
the nervous and mufcular fibres with principles
eflential to fenfibility and irritability.
Oxygene, which is capable of being refpired
for a much greater length of time than any
other gas, except common air, finally deflroys
life ; firft producing changes in the blood,
conneded with new living adlion.-f*
After experiments, to be detailed hereafter,
made upon myfelf and others, had proved that
nitrous oxide was refpirable, and capable of
* As appears from the experiments of Dr. Beddoes ;
likewife thofe of Mr. Watt.
+ As appears from the experimeHts of Lavoifier and Dr.
Beddoes ; and as will be feen hereafter.
( 336 )
fupporling life for a longer time than any
of the gafes, except atmofpheric air and oxygene,
I was anxious to afcertain the efFeds of it upon
aninnals^ in cafes where its adlion could be
carried to a full extent ; and to compare the
changes occafioned by it in their organs, with
thofe produced by other powers.
II. On the refpiration of Nitrous Oxide by
warm-hlooded Animals,
The nitrous oxide employed in the following
experiments, was procured from nitrate of am-
moniac, ^ and received in large jars, filled with
water previoufly faturated with the gas. The
animal was introduced into the jar, by being
carried under the water ; after its introdudion,
the jar was made to reft on a fhelf, about half
an inch below the furface of the water ; and the
animal carefully fupported, fo as to prevent
his mouth from refting in the water.
This mode of experimenting, either under
water or mercury, is abfolutcly neceflary, to
( 337 )
afoertaln with accuracy the efFeilvS of pure gafe^
on living beings. In fomc experiments that I
made on the refpiration of nitrous oxide, by
animals that were plunged into jars of it opened
in the atmofphere, and immediately clofed after
their introdudion, the unknown quantities of
common air carried in, were always fufficient
to render the refults perfdflly inaccurate.
Animals fufFer little or nothing by being pafied
through water.
That the phsenomena in thefe experiments
might be more accurately obferved, two or three
perfons were always prefent at the time of their
execution, and an account of them was noted
down immediately after.
a, A flout and healthy young cat, of four
or five months old, was introduced into a large
jar of nitrous oxide. For ten or twelve moments
he remained perfe6ily quiet, and then began
to make violent motions, throwing himfelf round
the jar in every direflion. In two minutes he
appeared quite exhaufted, and funk quietly to
the bottom of the jar. On applying my h^md
X
( 338 )
to the thorax, I found that the heart beat with
extreme violence ; on feeling about the neck, I
could diftincily perceive a flrong and quick
pulfation of the carotids. In about three
minutes the animal revived, and panted very
much ; but flill continued to lie on his fide.
His infpirations then became longer and deeper,
and he fometimes uttered very feeble cries. In
four minutes the pulfations of the heart appeared
quicker and feebler. His infpirations were at
long intervals, and very irregular ; in five
minutes the pulfe was hardly perceptible ; he
made no motions, and appeared wholly fenfelefs.
After five minutes and quarter he was taken out,
and expofed to the atmofphere before a warm
fire. In a few feconds he began to move, and
to take deep infpirations. In fivQ minutes
he attempted to rife on his legs ; but foon fell
again, the extremities being fiightly convulfed.
In eight or nine minutes he was able to walk,
but his motions were fl:aggering and unequal,
the right leg being convulfed, whilfl the other
was apparently ftifF and immoveable ; in about
( 339 )
Balfan hour lie was almoft aompletely recovered^
h> A healthy kitten, of about fix weeks oldy
Was introduced into nitrous oxide. She very
foon began to make violent exertions, and ia
lefs than a minute fell to the bottom of the
receiver, as if apopledlic. At this moment,
applying my hand to her fide, I felt the heart
beating with great violence. She continued
gafping, with long infpirations, for three
minutes and half; at the end of five minnte&
and half fhe was taken out completely dead.
c. Another kitten of the* fame breed was
introduced into nitrous Oxide, the day after.
She exhibited the fame phaenomena, and died
in it in about ^^^ minutes and half.
d. A fmall dog that had accidentally me^
with a diflocation of the vertebrae of the loins,
and was in great pain, as manifefied by his
moaning and whining, was ifitroduced into f|
large jar of nitrous oxide. He immediately
became quiet, and lay on his {\d.Q, in the jar,
breathing very deeply. In four minutes hi^
tefpiration became noify, and his eyes fparkU4
( 340 )
very much. I was not able to apply my hand
to the thorax. In five minutes he appeared
fenfelefs, and in feven minutes was perre6^ly
dead.
e, A (Irong rabbit, often or twelve months
old, was introduced into nitrous oxide. He
immediately began to ftruggle very much, and
in a minute fell down fenfelefs : in two minutes
the legs became convulfed, and his infpirations
were deep and noify : in lefs than five minutes
he appeared perfectly dead.
/. A rabbit of a month old introduced into
nitrous oxide, became fenfelefs in lefs than a
minute ; the pulfations of the heart were very
flrong at this moment : they gradually became
weaker, and in three minutes and half the
animal was dead.
g. Another rabbit of the fame breed, after
being rendered fenfelefs in nitrous oxide in a
minute and half, was taken out. He foon
became convulfed ; in a minute began to breathe
quickly ; in two minutes attempted to rife, but
flaggered, and fell again on his fide. His hinder
( 341 )
legs were paralytic for near five minutes. In
twenty he had almoft recovered.
g, A middle fized guinea-pig was much con-
vulfed, after being in nitrous oxide for a minute.
In two minutes and half he was fenfelefs.
Taken out at this period, he remained for fome
minutes by the fide of a warm fire, without
moving ; his fore legs then became convulfed ;
his hind legs were perfe611y paralytic. In this
flate he continued, without attempting to rife
or move, for near an hour, vyhen he died.
h, A large and old guinea-pig died in nitrous
oxide, exhibiting the fame phaenomena as the
other animals, in about five minutes and quar-
ter. A young one was killed in three minutes
and half.
i, A fmall guinea-pig, after breathing nitrous
oxide for a minute and half, was taken out, and
placed before a warm fire. He was for a few
minutes a little convulfed ; but in a quarter of
an hour got quite Well, and did not relapfe,
k. A large moufe introduced into nitrous
oxide, was for a few feconds very aflive. In
( 342 )
half a minVite be fell down fenfelefs ; in a minute
and quarter he appeared perfedily dead.
/. A moufe taken out of nitrous oxide, after
being in it for half a minute, continued con-
vulfed for fome* minutes, but finally recovered.
m, A young hen was introduced into a veflel
filled with nitrous oxide. She immediately
began to ftruggle very much ; fell on her bread
in lefs than half a minute^ and in two minutes
was quite dead.
n, A goldfinch died in nitrous oxide in
lefs than a minute.
In each of thefe experiments a certain abforp-
tion of the gas was always perceived, the water
rifing in the jar during the rcfpiration of the
animal. From them we learn
ift. That nitrous oxide is deftruclive when
refpired for a certain time to the warm blooded
animals, apparently previoufly exciting them to
a great extent.
2dly. That when its operation is flopped
before complcat exhauftion is brought on, the
healthy living a<^ion is capable of being gra-
dually reproduced, by enabling the animal to
refpire atmofpheric air.
( 343 )
3(lly. That exhauflion and death is produ-
ced in the fmall animals by nitrous oxide fooner
than in the larger ones, and in young animals
of the fame fpecies, in a fhorter time than in
old ones, as indeed Dr. Beddoes had conjetSlured
a priori would be the cafe.
Moil of the animals dedroyed in thefe
experiments were examined after death ; the
appearances in their organs were peculiar. To
prevent unneceflary repetitions, an account of
them will be given in the fourth fedlion.
III. EffeBs of the respiration of Nitrous
Oxide upon animals ^ as compared with thofe
produced by their immerjion in Hydrogene and
Water,
Before the following experiments were made,
a number of circumftances had convinced me
that nitrous oxide adled on animals by produ-
cing fome pofitive change in their blood, con-
ne6led with new living a6lion of the irritable
and fenfitive organs, and terminating in their
death.
( 344 )
To afcertain however, the difference between
the efFe(5ls of this gas and thofe of hydrogene
and non-refpirable gafes, I proceeded in the
following way.
a. Of two healthy rabbits of about two
months old, of the fame breed, and nearly of
the fame fize.
One was introduced into nitrous oxide. In
a half a minute, it had fallen down apparently
fenfelefs. On applying my hand to the thorax,
the a6lion of the heart appeared at firfl, very
quick and ftrong, it gradually became weaker,
and in two minutes and half, the animal was
taken out quite dead.
The other was introduced into a jar of pure
hydrogene through water. He immediately
began to ftruggle very much, and in a quarter
of a minute fell on his fide. On feeling the
thorax, the pulfations of the heart appeared very
quick and feeble, they gradually diminifhed ;
his breathing became momentarily fhorter, and
in rather more than three quarters of a minute,
he was taken out dead. Dr. Kinglake was
( 345 )
prefent at this experiment, and afterwards
difleded both of the animals,
h. Of two iimilar rabbits of the fame breed,
nearly three months old. One was introduced
into nitrous oxide, and after being rendered
fenfelefs by the refpiration of it for nearly a
minute and half, was expofed to the atmof-
phere, before a warm fire. He recovered gra-
dually, but was occafionally convulfed, and had
a paralyfis of one of his hinder legs for fome
minutes : in an hour he was able to walk. The
other, after being immerged in hydrogene for
near half a minute, was reftored to the atmof-
phere apparently inanimate. In lefs than a
minute he began to breathe, and to utter a
feeble noife ; in two minutes was able to walk,
and in lefs than three minutes appeared perfedly
recovered.
b, A kitten of about two months old, was
introduced into a jar of nitrous oxide, at the
fame time that another of the fame breed was
plunged under a jar of water. They both
ilruggled very much. The animal in the nitrous
( 346 )
oxide fell fenfelefs before that under water had
ceafed to ftruggle, and to throw out an* from
its lungs. In two minutes and three quarters,
the animal under water was quite dead : it was
taken out and expofed to heat and air, but did
not fhew the flighteft figns of life. At the end
of three minutes and half, the animal in nitrous
oxide began to gafp, breathing very flowly ;
at four minutes and three quarters it was yet
alive; at the end of five minutes and quarter
it appeared perfedly dead. It was taken out,
and did not recover.
From thefe experiments it was evident, that
animals lived at leaft twice as long in nitrous
oxide as in hydrogene or water. Confequently
from this circumftance alone, there was every
reafon to fuppofe that their death in nitrous
oxide could not depend on the fimple privation
of atmofpheric air ; but that it was owing to
fome peculiar changes eifedled in the blood by
the gas.
( 347 )
IV. Of the changes effeBed in the Organija-
ilon of warm-Hooded Anhnals, by the refplratmi
of Nitrous Oxide.
The external appearance of animals that have
been deftroyed in nitrous oxide, is very little
different from that of thofe killed by privation
of atmofpheric air. The fauces and tongue
appear of a dark red, and the eyes are dull^ and
a little protruded. Their internal organs, how-
ever, exhibit a very peculiar change. The
lungs are pale brown red, and covered here
and there with purple fpots ; the liver is of a
very bright red, and the mufcular fibre in
general dark. Both the auricles and ventricles
of the heart are filled with blood. The auricles
contra6lforminutes after the death of the animal.
The blood in the left ventricle, and the aorta, is of
a tinge between purple and red, whilfl that in
the right ventricle is of a dark color, rather more
purple than the venous blood. But thefe appear-
ances, and their caufes, will be better undcrflood
after the following comparative obfervatioiis ar^
read.
( 348 )
a. Of two fimilar rabbits, about eight months
old, one A, was killed by expofure for near fix
minutes to nitrous oxide , the other, B, was
deftroyed by a blow on the head.
They were both opened as fpeedily as poffible.
The lungs of B were pale, and uniform in
their appearance; this organ in A was redder, and
every where marked with purple fpots. The
liver of A was of a dark and bright red, that of
B of a pale red brown. The diaphragm of B,
when cut, was ftrongly irritable; that of A
rather darker, and fcarce at all contradile.
All the cavities of the heart contrad^ed for more
than 50 minutes in B. The auricles contraded
for near lb minutes with force and Velocity in A:
but theventricles were almoft inadive. The vena
cava, and the right auricle, in A, were filled with
blood, apparently a fhade darker than in B, The
blood in the left auricle, and the aorta, appeared
in A of a purple, a (hade brighter than that of the
venous blood. In the left auricle of B it was red.
I opened the head of each, but not without
injuring 'the brains, fo that I was unable to
( 349 )
make any accurate comparifon. The color of
the brain in A appeared rather darker than
in B.
b. Two rabbits, C and D, were deftroyed,
C by immerfion in nitrous oxide, D in hydro-
gene: they were both difledied by Dr. King-
iake. The blood in the pulmonary vein and
the left auricle of C was of a different tinge,
from that in D more inclined to purple red.-
The membrane of the lungs in C was covered
with purple fpots, that of D was pale and
uniform in its appearance. The brain in C
was rather darker than in D ; but there was no
perceptible efFufion of blood into the ventricles
either in D or C, The liver in C was of a
brighter red than in health, that in D rather
paler.
c. In the laft experiment, the comparative
irritability of the ventricles and auricles of the
heart and the mufcular fibre in the tv/o ani-
mals, had not been examined. That thefe
circumftances might be noticed, two rabbits,
E and F were killed ; E under water in about
( 350 )
a minute, and F in nitrous oxide in three,
minutes. They were immediately openedy
and after a minute, the appearance of the
heart, and organs of rcfpiration obferved.
Both the right and left ventricles of the heart
in F contraded but very feebly ; the auricles
regularly and quickly contradled ; the aorta
appeared perfedily full of blood. In E, a feeble
contra6lion of the left finus venosus and
auricle was obferved ; the left ventricle did
not contradl : the right contradled, but
more llowly than in F. In a few minutes^
the contractions of the ventricles in F had
ceafed, whilst the auricles contradled as
flrongly and quickly as beforci The blood in
the pulmonary veins of F was rather of a red-
der purple than in E ; the difference of the
blood in the vena cava was hardly perceptible,
perhaps it was a little more purple in F. The
membranous fubftance of the lungs in F was
fpotted with purple as from extravafated blood,
whilft that in E was pale. The brain in F was
darker than in E. On opening the ventricles
no extravafation of blood v^as perceptible.
( 351 )
The auricles of the heart in F contra(^ed
ftrongly for near twenty minutes, and then
gradually their motion became lefs fre-
quent ; in twenty-eight minutes it had
wholly ceafed. The right auricle and ventri-
cle in E, occafionally contra<^ed for half an
hour. The livers of- both animals were fimilar
when they were firft opened, of a dark red ;
that of F preferved its color for fome time
when expofed to the atmofphere ; whllfl that
ofEalmoft immediately became paler under
the fame circumftances.
The periftaltic motion continued for nearly
an equal time in both animals.
d. The fternum of a young rabbit was re-
moved fo that the heart and lungs could be
perceived, and he was introduced into a veiiei
filled with nitrous oxide ; the blood in the
pulmonary veins gradually became o)ore purple,
and the heart appeared to beat quicker than
before, all the mufcles contradiing with'
great force. • After he had been in about
a minute, fpots began to appear on the iungs^
( 352 J
though the contra6lions of the heart became
quicker and weaker ; in three minutes and
half he was quite dead; after death the ventri-
cles contraded very feebly, though the con-
tractions of the auricles were as ftrong almoft
after the end of five minutes as at firft. This
animal was palled through water faturated with
nitrous oxide ; poflibly this fluid had fomc
efFc6l on his organs.
Befides thefe animals, many others, as
guinea-pigs, mice and birds, were diffedled
after being deftroyed in nitrous oxide ; in all
of them the fame general appearance was
obferved. Their mufcular fibre almofl always
appeared Icfs irritable than that of animals
deftroyed, by organic teflon of part of the ner-
vous fyftem, in the atmofphere. The ventricles
of the heart in general, contrafled feebly and
for a very Qiort time ; whilfl the auricles con-
tinued to a6l for a great length of time. The
lungs were dark in their appearance, and
always fufFufed here and there with purple ;
the blood in the pulmonary veins when flightly
( 353 )
obferved, appeared dark, like venous blood, but
when minutely examined, was evidently much
more purple. The blood in the vena cava,
was darker than that in the pulmonary veins.
The cerebrum was dark.
In a late experiment, I thought 1 perceived
a flight extravafation of blood in one of the
ventricles of the brain in a rabbit deftroyed
in nitrous oxide ; but as this appearance had not
occurred in the animals I had examined before,
or in thofe difledied by Dr. Kinglake, and Mr.
King, Surgeon, I am inclined to refer it to an
accidental caufe. At my requeft^ Mr. Smith,
Surgeon, examined the brain of a young rabbit
that had been killed in his prefence in nitrous
oxide ; he was of opinion that no efFuGon of
blood into the ventricles had taken place.
In comparing the external appearance of the
crural nerves in two rabbits that had been dif-
fered by Dr. Kinglake, having been deftroyed
one in hydrogene, the other in nitrous oxide,
we could perceive no perceptible difference.
It deferves to be noticed, that whenever the
■^ •' ^^'
( 354 )
gail bladder and the urinary bladder have been
examined in animals deftroyed in nitrous oxide.^
they have been always difl ended with fluid ;
which is hardly ever^he cafe in animals killed by
privation of atmofpheric air.
In the infancy of my experiments on the
a6lion of nitrous oxide upon animals, I thought
that it rendered the venous blood lefs coagu-
lable; but this I now find to be a miftake. The
blood from the pulmonary veins of animals kil-
led in nitrous oxide, does not fenfibly differ in
this refped from the arterial blood of thofe de-
ftroyed in hydrogene, and both become ver-
milion nearly in the fame time when expofcd t©
the atmofphere.
In defcribing the various fhades of color of
the blood in the preceding obfervations on the
different dilTecSed animals, the poverty of the
language of color, has obliged me to adopt
terms, which I fear will hardly convey to the
mind of the reader, diftin6l notions of the
differences obfervable by minute examina-
tion in the venous and arterial blood of
( 353 )
animals that die of privation of atmofpheric
air, and of thofe deftroyed by the adlion of
nitrons oxide. This difference can only be
obferved in the vcf!cls- by means of a ftrong
light ; it may however be eafily noticed in the
fluid blood by the introduction of it from the
arteries or veins at the moment of their inci-
fion, between two polifhed furfaces of white
glafs^* {o clofely adapted to each other, as to
prevent the blood from coming in contadl witli
the atnlofphere.
Having four or five times had an opportunity
of bleeding people in the arm for trifling com-
plaints^ I have always received the blood in
phialsj filled with various gafes, in a mode
to be defcribed hereafter. Venous blood
agitated in nitrous oxide, compared with fimi«
lar blood in common air, hydrogene, and ni-
trogene, was always darker and more purple
^ The colour of cottimon venous blood, examined in
this way, refembles that of the paint called by cclour-men
red ochre j that of blood faturated with nitrons oxide^ ap-
proaches to the tinge of Jake,
^—
~III^M|- T
( 356 )
than the firfl, and much brighter and more
florid than the two lad, which were not differ-
ent in their color from venous blood, received
between two furfaces of glafs. It will be ieQ,n
hereafter, that the coagulum of venous blood
is rendered more purple when expofed to ni-
trous oxide, whillt the gas is abforbed ; likewifc
that blood altered, by nitrous oxide, is capable
of being again rendered vermilion, by expo-
fure to the air.
The appearances noticed in the above men-
tioned experiments, in the lungs of animals
deftroyed in nitrous oxide, arefimilar to thofe
obferved by Dr. Beddoes, in animals that had
been made to breathe oxygene for a great
length of time.
There were many reafbns for fuppofing that
the large purple fpots in the lungs of animal*
deftroyed in nitrous oxide, were owing to ex-
travafation of venous blood from the capillary
veflels ; their coats being broken by the highly
increafed arterial a6lion. To afcertain whether
thefe phsenomena exiflcd at a period of tb<i
( 357 )
•adlion of nitrous oxide, when the animal was
o-ecoverable by expofure to the atmofphere,
I introduced a rabbit of fix months old, into
a veflel of nitrous oxide, and after a minute,
when it had fallen down apparently apopledlic,
plungedhimwhollyunderwater; he immediately
began to ftruggle, and what furprifed me very
much, died in lefs than a minute after fubmer-
fion. On opening the thorax, the blood in the
pulmonary veins was nearly of the color of that
in animals that have been fimply drowned.
The lungs were here and there, marked with a
few points ; but there were no large purple
fpots, as in animals that have been wholly
deftroyed in nitrous oxide : the right fide of
the heart only contradied. In this experiment,
the excitement from the action of the gas was
probably carried to fuch an extent, as to pro-
duce indiredl debility. There are reafons for
fuppofing, that animals after having been ex-
cited to but a fmall extent by the refpiration of
nitrous oxide, will live under water for a greater
length of time, than animals previoufly made to
breathe common air.
( 358 )
V. Of the refpiralion of mixtures of Mlrous-
Oxide, and other gafeSy hy warm-blooded Animals.
a, A rabbit of near two months old, was
introduced into a mixture of equal parts hydrp-
gene and nitrous oxide through water. He
immediately began to ftruggle ; in a minute
fell on his fide ; in three minutes gafped, and
made long infpirations ; and in four minutes
and half, was dead. On di (Ted) ion, he exhibited
the fame appearances as animals deflroyed in
nitrous oxide.
h. A large and ftrong moufe w;is introduced
into a mixture of three parts hydrogene to one
part nitrous oxide. He immediately began to
flruggle very much, in half a minute, became ^
convulfed, and in about a minute, was quite
dead.
c. Into a mixture of one oxygene, and three
nitrous oxide, a Anall guinea-pig was introdu-
ced. He immediately began to ftruggle, and
in two minutes repofed on his fide, breathing
very deeply^ Re made afterwards no violent
( 359 )
mufcular motion ; but lived quietly for near
fourteen minutes: at the end of which time,
his legs were much convulfed. He was taken
out, and recovered.
(h A moufe lived apparently without fufFer-
ing, for near ten minutes, in a mixture of l
atmofpheric air, and 3 nitrous oxide, at the end
of eleven minutes he began to ftruggle, and in
thirteen minutes became much convulfed.
e, A cat of three months old, lived for feven-
teen minutes, in a very large quantity of a mix*
ture of 1 atmofpheric air, and 12 nitrous oxide.
On her firft introdudlion fhe was very much
agitated and convulfed, in a minute and half
fhe fell down as if apopledic, and continued
breathing very deeply during the remainder
of the time, fometimes uttering very feeble
cries. When taken out, fhe appeared almofi:
inanimate, but on being laid before the fire,
gradually began to breathe and move ; being
for fome time, like mod of the animals that have
recovered after breathing nitrous oxide, con^
yulfed on one fide, and paralytic the other.
( 360 )
y. A goldfinch lived for near five minutes in
a mixture of equal parts nitrous oxide and oxy-
gene, without apparently fuffering. Taken
out, he appeared faint and languid, but finally
recovered.*
"VI. Recapitulation of fa3s relating to the
refpiration of Nitrous Oxide, by warm-blooded
Animals.
1. Warm-blooded animals die in nitrous
oxide infinitely fooner than in common air or
oxygene ; but not nearly in fo fhort a time as
in gafes incapable of efFedling pofitive changes
in the venous blood, or in non-refpirable
gafes.
2. The larger animals live longer in nitrous
oxide than the fmaller ones, and young animals
* Small birds fufFer much from cold when introduced
into gafes through water. In this experiment, the gold-
finch was immediately inferted into a large mouthed
phial, filled with the gafes, and opened in the atniof-
phcre.
^r J— ...J— .-i
( 361 )
die in it fooner than old ones of the fame
fpecies.
.3. When animals, after breathing nitrous
oxide, are removed from it before compleat
exhauftion has taken place, they are capable of
being reflored to health under the action of
atmofpheric air.
4. Peculiar changes are efFedied in the organs
of animals by the refpiration of nitrous oxide.
In animals deftroyed by it, the arterial blood
is purple red, the lungs are covered with purple
fpots, both the hollow and compact mufcles
are apparently very inirritable, and the brain is
dark colored.
5. Animals are deftroyed by the refpiration
of mixtures of nitrous oxide and hydrogene
nearly in the fame time as by pure nitrous ox-
ide ; they are capable of living for a great length
of time in nitrotjs oxide mingled with very mi-
nute quantities of oxygene or oommon air.
Thefe fails will be reafoned upon in the next
divifion.
( 362 )
VII. Of tie refpiration of Nitrons Oxide hy
amphihioiis Animals.
As from the foregoing experiments, it ap-
peared that the nitrous oxide deflroyed warm-
blooded animals by increafing the living aflion
of their organs to fiich an extent, as finally to
exhaull their irritability and fenlibility ; it was
reafonable to conje6ture that the cold-blooded
animals, poilefled of voluntary power over ref-
piration, would fo regulate the quantity of
nitrous oxide applied to the blood in their lungs
BS to bear its allien for a great length of time.
This conje(?ture was put to the teft of experi-
ment; the following fadls will prove its error.
a. Of two middle-fized water-lizards, one was
introduced into a fmall jar filled with nitrous
oxide, over moifl mercury, by being paflcd
throqgh the mercury ; the other was made to
breathe hydrogene, by being carried into it in
the fame manner.
The lizard in nitrous oxide, in two or three
minutes, began to make violent motions, ap-
rxar^
( 363 )
peared very unenfy, and rolled about the jar in
every direflion, fometimes attempting to climb
to the, top of it. The animal in hydrogene was
all this time very quiet, and crawled about the
veflel without being apparently much afFefled.
At the end of twelve minutes, the lizard in
nitrous oxide was lying on his back feemingly
dead ; but on agitating the jar he moved a little ;
at the end of fifteen minutes he did not move
on agitation, and his paws were reftingonhisbelly.
He was now taken out fiifF and apparently life-
lefs, but after being expoled to the atmofphcrc
for three or four minutes, took an infpira-
tion, and moved his head a little ; he then
raifed the end of his tail, though the middle of
it was (till ftifFand did not bend when touched.
His four legs remained clofe to his fide, and
were apparently ufelefs ; but on pricking them
with the point of a lancet, they became con-
vulfed. After being introduced into fhallow
water, he was able to crawl in a quarter of
an hour, though his motions were very irre-
gular. In an hour he was quite well. The
•ifciMihrrii'^- 'inii-^irnTTtfrirr^
{ 3t)4 )
animal in hydrogene appeared to have fuffered
very little in three quarters of an hour, and
had raifed himfelf againft the fide of the jar.
At the end of an hour he was taken out, and
very foon recovered.
h. Some hours after, the fame lizards were
again experimented upon. That which had
been inferted into hydrogene in the laft
experiment, being now inferted into nitrous
oxide.
This lizard was apparently lifelefs in fourteen
minutes, having tumbled and writhed himfelf
very much during the firft ten minutes. Taken
out after being in twenty-five minutes, he did not
recover. The other lizard lived in hydro-
gene for near an hour and quarter, taken out
after an hour and twenty minutes, he was dead.
Thefe animals were both opened, but the
vifcera of the nitrous oxide lizard were fo much
injured by the knife, that no accurate compa-
rifon of them with thofe of the other could be
made, I thought that. the lungs appeared rather
redder.
-_ i!^'*ii:i^j i-XL.
( 365 )
a. Of two fimilar large water-lizards, one
was introduced into a veflel Handing over mer-
cury, wholly filled with water that had been
long boiled and fufFered to cool under mercury.
The animal very often rofe to the top of the
jar as, if in fearch of air, during the firft half
hour ; but (hewed no other figns of uneafinefs.
At the end of three quarters of an hour, he
became very weak, and appeared fcarcely able
to fwim in the water. Taken out at the end
of fifty minutes, he recovered.
The other was inferted into nitrous oxide.
After much ftruggling, he became fenfelefs
in about fifteen minutes, and lay on his back.
Taken out at the end of twenty minutes, he
remained for a long time motionlefs and fiifF,
but in a quarter o^ an hour, began to move
fome of his limbs.
From thefe experiments, we may conclude,
that water-lizards, and moft probably the other
amphibious animals, die in nitrous oxide in a
much fhorter time than in hydrogene or pure
water ; confequently their death in it cannot
( 366 )
depcndon the fimple privation of atmofpheiic air.
At the feafon of the year in which this in-
veftigation was carried on, I was unable to
procure frogs or toads. This I regret very much.
Suppofing that cold-blooded animals die
in nitrous oxide from politive changes ef-
fedied in their blood by the gas, it would be
extremely interefting to notice the apparent al-
terations taking place in their organs of refpira-
tion and circulation during its adlion, which
could ealily be done, the membranous fubftance
of their lungs being tranfparent. The increafe or
diminution of the irritability of their mufcular
fibre, might be determined by comparative gal-
vanic experiments.
VIII. EffeBs of fohtion of nitrous oxide in
water on Fifhes,
a, A fmall flounder was introduced into a
vefTel filled with folution of nitrous oxide in
water over mercury. He remained at refl: for
ten minutes and then began to move about the
( 367 )
jar in different directions. In a half an hour he
was apparently dying, lying on his, fide in the
water. He was now taken out, and introduced
into a veflel filled with water faturated with
common air, he very Toon recovered.
h. Of two large thornbacks,^^ equally brifk
and lively. One, A, was introduced into a jar
containing nearly 3 cubic inches of water,
faturated with nitrous oxide, and which pre-
vious to its impregnation had been long boiled ;
the other, B, was introduced into an equal
quantity of water which had been deprived of
air by diftillation through mercury.'
A, appeared very quiet for two or three
minutes, and then began to move up and down
in the jar, as if agitated. In eight minutes his
motions became very irregular, and he darted-
obliquely from one fide ofthe jar to the other.
•^ I ufe the popular name. This fiili is very common in
every part of England 3 it is nearly of the fame fize and
color as the minnow, and is diftinguilhed from it by two
fmall bony excrefences at the origin of the belly. It H
extremely fufceptible.
( 368 )
In twelve minutes, he became ftill^ and moved
his gills very llowly. In fifteen minutes he
appeared dead. After fixteen minutes he was
taken out, but (hewed no figns of life.
B was very quiet for four minutes and half.
He then began to move about the jar. In
feven minutes he had fallen on his back, but
ftill continued to move his gills. In eleven
minutes he v^as motionlefs ; taken out after
thirteen minutes, he did not recover.
c. Of two thornbacks, one, C was introduced
into about an ounce of boiled water in contadl
with hydrogene, fianding over mercury. The
other, D, was introduced into well boiled wa-
ter faturated with nitrous oxide, and (landing
in contaft with it over mercury. C lived near
thirteen minutes^ and died without being pre-
vioufly much agitated. D was apparently
motionlefs, after having the fame afFedlions as
A in the laft experiment, in fixteen minutes.
At the end of this time he was taken out and
introduced into common water. He foon began
to move his gills, and in lefs than a quarter of
( 369 )
an hour was Co far recovered as to be able to
fwim.
The laft experiment was repeated on two
fmaller thornbacks ; that in the aqueous iblution
of nitrous oxide lived near fcventeen minutes,
that in the water in contadl with hydrogene^
about fifteen and half.
The experiments in Ref. I. Div. 3, prove
the difficulty, and indeed almofl impoffibility of
driving from water by boiling, the whole of the
atmofpheric air held in folution by it ; they
likewife (how that nitrous oxide by its flrong
affinity for water, is capable of expelling air from
that fluid after no more can be procured from it
by ebullition.
Hence, if water faturated with nitrous oxide
had no pofitive effedls upon fifhes ; they ought
to die in it much fooner than in water deprived
of air by ebullition. From their living in it rather
longer;* we may conclude^ that they are de-
ilroyed not by privation of atmofpheric air, but
* A priori I expe6ted that fitlieS;, like amphibious ani-
mals would have been very quickly deftroyed by the a6tioa
of nitrous oxide.
Z
( 370 )
from Ibme pofitive change efFeSed in their
blood by the gas.
A long while ago, from obferving that the
gills of filli bec»?he rather of a lighter red du-
ring their death, in the atmofphere ; I con-
jedlured that the difeafe of which they died,
was probably hyperoxygenation of the blood
conne6led with highly increafed animal heat.
For not only is oxygene prefented to their
blood in much larger quantities in atmofphe-
ric air than in its aqueous folution ; but like-
wife, to ufe comm.on language, in a ftate in
which it contains much more latent heat.
Without however laying any ftrefs on this
fuppofition, I had the curiofity to try whether
thornbacks would live longetl in atmofpheric
air or nitrous oxide. In one experiment, they
appeared to die in them nearly in the fame
time. In another, the fifli in nitrous oxide lived
nearly halfaslongagain as that in atmofphericair.
XL Effe&s of Nitrous Oxide oti Inje6ts.
The winged infefls furnitlied with breathing
( 371 )
holes, become molionl^fs in nitrous o;;ide very
fpeecllly ; being however pofTeiTecl of a certain
voluntary power over relpiration, they fometimes
rccovtr, after having been expofed to it for fome
minulcp, under the action of atmofpheric air.
A butterfly was introduced into a fmall jar,
filled with pure nitrous oxide, over mercury.
He ftruggied a little during the firft two or
three fcconds ; in about feven fcconds, his leg^
became convulfed, and his wings were wrapt
round his body ; in about half a minute he
was fenfelefs ; taken out after fix minutes, he
did not recover.
Another butterfly introduced into hydrogene,
became convulfed in about a quarter of a minute^
was fenfelefs in twenty fcconds, and taken out
after five minutes, did not revive.
A large drone, after being in nitrous oxide
for a minute and a quarter, was taken out fenfe-
lefs. After being for fome time expofed to the
atmofphere, he began to move, and at lafl rofe
on his wings. For fome time, however, he was
xmable to fly in a ftraight line ; and often after
( 372 )
defcribing circles in the air, fell to the ground
as if giddy.
A large fly, became motionlefs in nitrous
oxide after being convulfed, in about half a mi-
nute. Another was rendered fenfelefs in hydro-
gene, in lefs than a quarter of a minute.
A fly introduced into hydrocarbonate, dropt
immediately fenfelefs ; taken out after about a
quarter of a minute, he recovered ; but like the
fly that had lived after expofure to nitrous
oxide, was for fome time vertiginous.
Flies live much longer under water, alco-
hol, or oil, than in non-refpirable gafes, or
gafes incapable of fupporting life. A certain
quantity of air always continues attached in the
fluid to the fine hairs furrounding their breathing
holes, fufficient to fupport life for a fliort time.
Snails and earth-worms, live in nitrous oxide
a long while , they die in it however, much
fooner than in water or hydrogene ; probably
from the fame caufes as the amphibious animals.
DIVISION II.
Of the CHANGES effected in NITROUS OXIDE,
and other GASES, by the RESPIRATION of
ANIMALS.
i
I. Prelimifiaries.
xVs loon as I had difcovered that nitrous oxide
was refpirable, and pofTefTed of extraordinary
powers of action dn living beings, I was anxious
to be acquainted with the changes efFedled in
it by the venous blood. To invefligate thefe
changes, appeared at firft a fimple problem ;
I foon however found that it involved much
preliminar)' knowledge of the chemical proper-
ties and affinities of nitrous oxide. After I had
afcertained by experiments detailed in the pre-
ceding Refearches, the compofition of this gas
(374 )
its combinations, and the phyfical changes
efFedled by it in living beings, I began my en-
quiry relating to the mode of its operation.
Finding that the refidual gas of nitrous oxide
after it had been breathed for fome time in filk
bags, was chiefly nitrogene, I at firft conjec-
tured that nitrous oxide was decompofed in
refpiration in the fame manner as atmofpheric
air, and its oxygene only combined with the
venous blood ; the folloVing experiments foon
however convinced me of my erron
11. AhforptiGn of Nitrous Oxide hy venous
Hooch Changes effected in the blood by dif-
ferent Gafes,
a. Though the laws of the coagulability of
the blood are unknown, yet we are certain
that at the moment of coagulation, a per-
fectly new arrangement of its principles takes
place ; confcquently, their powers of combina-
tion muft be newly modified. The affinities of
( 375 )
living blood can only be afcertained during its
circulation in the veilels of animals. At the
moment of effiifion from thofe veffels, it begins
to pafs through a feries of changes, which
firft produce coagulation, and finally its com-
pleat decompofition.
Confequently, the aflion of fluid blood upon
gafes out of the veflels, will be more analogous
to that of circulating blood in proportion as it is
more fpeedily placed in contadl: with them.
b. To afcertain the changes efFeded in ni
trous oxide by fluid venous blood.
Ajar, fix inches long and half an inch wide^
graduated to ,05 cubic inches, having a tight
fl:opper adapted to it, was filled with nitrogene,
which is a gas incapable of combining with, and
pofleflingno power of a*fl ion upon venous blood.
A large orifice was made in the vein of a tole-
rably healthy man, and the Itopper removed
from the jar, which was brought in contad with
the arm fo as to receive the blood, and prefTed
clofe againfl the fkin, in fuch a way as to leave an
orifice jufl fuflicient for the efcape of the nitro-
( 370 )
gene^ as the blood flowed in. When the jar was full^
it was clofed, and carried to the pneumatic;
apparatus, the mercury of which had been pre-
vioufly a little warmed. A fmall quantity of
the blood was transferred into another jar tq
make room for the gas. The remaining quantity
equalled exadly two cubic inches ; to this was
introduced as fpeedily as pofQble, eleven mea-
fures equal to ,55 cubic inches of nitrous oxide,
which left a refiduum of — only, when abforb-
ed by boiled water, and was confequently, per-
fedlly pure. On agitation, a rapid diminution
of the gas took place.
In the mafs of blood which was opaque,
but little change of color could be perceived ; but
that portion of it diffufed over the tides of the
jar, was evidently of a brighter purple than the
venous blood.
It was agitated for two or three minutes, and
then fufFered to refi^ ; in eight minutes it had
wholly coagulated ; a fmall quantity of fe-
rum had fcparated, and was diffufed over thq
coagulum. This coagulum was dark; but
( 37; ) '
evidently of a more purple tinge than that of
venous blood ; no gas had apparently been libe-
rated during its formation.
The nitrous oxide remaining, was not quite
equal to feven meafures ; hence, at lead four
meafures of it had been abforbed.
To afcertain the nature of the refiduum, it
was neceflary to transfer it into another veffel ,
but this I found very difficult to accomplifh, on
account of the coagulated blood. By piercing
through the coagalum and removing part
of it by means of curved iron forceps, I
at lafi: contrived to introduce about 4^ mea-
fures of the gas into a fmall cylinder, gra-
duated to ,"25 cubic inches, in which it occu-
pied of courfe, nearly Q meafures ; when a lit-
tle folution of ftrontian was admitted to thefe,
it became very flightly clouded ; but the abforp-
tion that took place did not more than equal
half its bulk. Confequently, the quantity of
carbonic acid evolved from the blood, or formed,
inuft have been extremely minute.
On the introdudion of pure water, a rapid
( 378 )
abforption of the gas took place, and after agi-
tation, not quite 3 meafures remained. Thefe
did not ^erceptihly diminifh with nitrous gas ;
their quantity was too fmall to be examined by
any other teft ; but there is reafon to fuppofe
that they were chiefly compofed of nitrogene.
From this experiment, it appeared that ni-
trous oxide is abforbed when placed in contadl
with venous blood ; at the fame time, that i
very minute quantity of carbonic acid and
probably nitrogene is produced.
c. In another fimilar experiment when nearly
half a cubic inch of nitrous oxide was abforbed
by about a cubic inch and three quarters of
fluid blood, the refidual gas did not equal more
than — , the quantity abforbed being taken as
unity. This fa6l induced me to fuppofe that
the abforption of nitrous oxide by venous blood,
was owing to a (imple folution of the gas in that
fluid, analogous to its folution in water or alcohol.
To afcertain if nitrous oxide could be ex-
pelled from blood impregnated with it, by
heat : I introduced to 1 cubic inches of fluid
( 379 )
blood taken from the medial vein, about ,6
cubic inches of nitrous oxide. After agitation,
in feven minutes nearly ,4^were abforbed. In
ten minutes, after the blood had completely
coagulated, the cylinder containing it, was
transferred in conta(5l with mercury, into a veiTel
offolution of fait in water; this folution was
heated and made to boil. During its ebullition,
the whole of the blood became either white or
pale brown, and formed a folid coherent
mafs ; whilft fmall globules of gas were given
out from it. In a few minutes, about ,25 of
gas had colleded. After the veflel had cooled,
I attempted to transfer this gas into a fmall
graduated jar in the mercurial apparatus, but
in vain ; the mafs in the jar was fo folid and
tough, that I could not remove it. By tranf-
ferring it to the water apparatus, I fucceeded in
difplacing enough of the coagulum to fufFer
the water to come in contad with the gas ; an
abforption of nearly half of it took place ; hence,
J conjeBure^ that nitrous oxide had been given
out by the impregnated blood.
( 380 )
d. Some frefh dark coagulum of venous
blood, was expofed to nitrous oxide. A very
flight alteration of color took place at the fur-
face of the blood, perceptible only in a flrong
light, and a minute quantity of gas was ah-
forbed. A taper burnt in the remaining gas
as brilliantly as before, hence, it had apparently
fufFered no alteration.
e. To compare the phyfical changes efFe6\ed
in the venous blood by nitrous oxide, with thofe
produced by other gafes, I made the follow-
ing experiments. — I filled a large phial, con-
taing near 14 cubic inches^ with blood from
the vein of the arm of a man, and immediately
transferred it to the mercurial apparatus. Dif-
ferent portions of it were thrown into fmall
graduated cylinders, filled with the following
gafes : nitrogcne, nitrous gas, common air,
oxygene, nitrous oxide, carbonic acid, and
hydrocarbonate.
The blood in each of them was fucceflively
agitated till it began to coagulate ; and making
allowances for the different periods of agitation^
( 381 )
there was no marked difference in the times of
coagulation.
The color of the coagukim in every part of
the cylinder, containing nitrogene, was the
fame very dark reel. When it was agitated fo
as to tinge the fides of the jar, it appeared
exa6lly of the color of venous blood received
between two furfaces of glafs ; no perceptible
abforption of the gas had taken place.
The blood in nitrous gas was dark, and much
more purple on the top than that in nitrogcne.
When agitated fo as to adhere to the jar as a
thin lurface^ this purple was evidently deep
and bright. An abforption of rather more
than ~ of the volume of gas had taken place.
The blood in oxygene and atmofpheric air,
were of a much brighter tinge than that in any
of the other gafes. On the top, the color was
vermilion, but no perceptible abforption had
taken place.
The coagulum in nitrous oxide, when exa-
mined in the mafs was dark, and hardly diftin-
guifhable in its color from venous blood ; but
when minutely noticed at thefurface where it was
( 382 )
covered with fer.um, and in its diffafion over
the fides of the jar, it appeared of a fine pur-
ple red, a tinge brighter than the blood in nitrous
gas. An abforption had taken place in this
cylinder, more confiderable than in any of the
others.
In carbonic acid, the coagulum was of a
brown red, much darker than the venous blood,
and a flight diminution of gas had taken place.
In the hydrocarbonate,* the blood was red,
a fhade darker than the oxygenated blood, and
a very flight diminution of the gas-}" was percep-
tible.
/. To human blood that had been fatura-
ted with nitrous oxide whilft warm and con-
flantly agitated for four or Ave minutes, to
prevent its uniform coagulation, oxygene was
introduced ; the red purple on the furface of it.
* The hydrocarbonate employed, was procured from
alcohol, by means of fulphurlc acid. This gas contains
more carbon, than hydrocarbonate from water and charcoal.
'[ The curious fa6t of the reddening of venous blood by
hydrocarbonate, was difcovered by Dr, Beddoes.
( 383 )
immediately changed to vermilion ; and on
agitation, this color was difFufed through it.
On comparing the tinge with that of oxygena-
ted blood, no perceptible difference could be
obferved. No change of volume of the oxy-
gene introduced, had taken place ; and confe-
quently, no nitrous oxide had been evolved
from the blood.
g. Blood, impregnated with nitrous gas, was
expofed to oxygene ; but after agitation in it
for many minutes, no change of its dark purple
tinge could be obferved, though a flight dimi-
nution of the oxygene appeared to take place.
^. Blood that had been rendered vermilion
in every part by long agitation in atmofpheric
air, the coagulum of which was broken and
diffufed with thecoagulable lymph through the
ferum, was expofed to nitrous oxide ; for fome
minutes no perceptible change of color took
place ; but by agitation for two or three hours,
it evidently affumed a purple tinge, whilft a
a flight abforption of gas took place. It never
( 381 )
however, became nearly fo dark as venous
blood that had been expofed to nitrous oxide.
i. Blood, oxygenated in the fame manner
as in the laft experiment, the coagulum of
which had been broken, was expofed to nitrous
gas. The furface of it immediately became
purple, and by agitation for a few minutes, this
color was diffufed through it. A flight dimi-
nution of the gas was obferved. On comparing
the tinge with that of venous blood that had
been previoufly expofed to nitrous gas, there
was no perceptible difference.
k. Blood expofed to oxygenated muriatic acid
is wholly altered in its conftitution and phyfical
properties, as has been often noticed ; the
coagulum becomes black in fome parts, and
brown and white in others. Venous blood, after
agitation in hydrogene or nitrogene, oxyge-
nates when expofed to the atmofphere in the
fame manner as fimple venous blood. I had
the curiofity to try whether venous blood
expofed to hydrogene, would retain its power
of being oxygenated longer than blood
( 385 )
Saturated with nitrous oxide : for this pufpofs
fome fimilar black coagulum was agitated for
fometimc in two phials, one filled with hydrogene,
the other with nitrous oxide. They were then
fufFered to re(l for three days at a temperature
from about 56° to 63". After being opened, no
ofFenfive fmell was perceived in either of them,
the blood in hydrogene was rather darker than
at the time of their expofure, whilft that in
nitrous oxide was of a brighter purple. Oa
being agitated for fome time in the atmofphere,
the blood in nitrous oxide became red, but not
of fo bright a tinge as oxygenated venous
blood. The color of the blood in hydrogene
did not at all alter.
/. To afcertain whether impregnation with
nitrous oxide accelerated or retarded the putre-
fadlion of the blood ; I expofed venous blood in
four phials, the firft filled with hydrocarbonate,
the fecond with hydrogene ; the third w^th atmof-
pheric air, and the fourth with nitrous oxide.
Examined after a fortnight, the blood in hydro-
gene and common air were both black, and flunk
Aa
( 386 )
very much ; that in hydrocarbonale was red*
and perfeflly fweet; ihatin nitrons oxide appear-
ed purple and had no difagreeable fmell.
In a fecond experiment, when blood was
expofed for three weeks to hydrocarbonate and
nitrous oxide, that in nitrous oxide was darker
than before and flunk a little ; that in hydro-
carbonate was flill perfe6ily fweet. The power
of hydrocarbonate to prevent the putrefadlicn
of animal matters, was long ago noticed by
Mr. Watt.
m. Having accidentally cut one of my fingers
fo as to lay bare a little mufcular fibre, I intro-
duced it whilft bleeding into a bottle of nitrous
oxide ; the blood that trickled from the wound
evidently became much more purple ; but the
pain was neither alleviated or increafed. When
however^ the finger was taken out of the nitrous
oxide and expofed to the atmofphere, the wound
fmarted more than it had done before. After it
had ceafed to bleed, I inferted it through wa-
ter into a vefTel of nitrous gas ; but it did not
become more painful than before.
( 387 )
From all thefe obfervations, we may conclude^j
ift. That when nitrous oxide is agitated in
fluid venous blood, a certain portion of the gas
is abforbed ; whilft the color of the blood
changes from dark red to red purple.
2dly. That during the abforption of nitrous
oxide by the venous blood, minute portions of
nitrogene and carbonic acid are produced, either
by evolution from the blood, or from a decom-
pofition of part of the nitrous oxide.
3dly. That venous blood impregnated with
nitrous oxide is capable of oxygenation ; and
vice verfa ; that oxygenated blood may be com-
bined with nitrous oxide.
When blood feparated into coagulum and
ferum, is expofed to nitrous oxide, it is moft
probable that the gas is chiefly abforbed by the
ferum. That nitrous oxide however is capable
ofa6ling upon the coagulum, is evident from
d. In the fluid blood, as we (hall fee hereafter,
nitrous oxide is abforbed by the attractions of
the whole compound.
^ftSm^iumtrntmrnm^m^mm^immmmtt^^i'''^!*^
( 388 )
III. Of tie changes effe^ed in Nitrous Oindt
hy Rejpration,
To afccrlain wbctbcr the changes efFe61ed in
nitrous oxide by the circulating blood acting
through the moid coats of the pulmonary vein^
of living animals, were highly analogous to
thofe produced in it by fluid venous blood
removed from the veflels, I found extremely
difficult.
I have before obferved, that when animals
are made to refpire nitrous oxide, a certain ab-
forption of the gas always takes place ; but the
fmaller animals, the only ones that can be
experimented upon in the mercurial apparatus,
die in nitrous oxide fo fpeedily and occafion fo
flight a diminution of gas, that T judged it
ufelefs to attempt to analife the refiduum of
their refpiration, which fupports flame as well
as pure nitrous oxide, and is chiefly abforba-
ble by water.
In the infancy of my refearches, I often
refpired nitrous oxide in a large glafs bell, fur-
( 389 )
Tirfliecl with a breathing tube and ftopcock, and
poifed in water faturated with the gas.
In two or three experiments in which thenof-
trils being clofed after the exhauftion of the
lungs, the gas was infpired from the bell and
refpired into it, a coniiderable diminution was
perceived, and by the teft of lime water fomc
carbonic acid appeared to have been fornied ;
but on account of the abforption of this carbo-
nic acid by the impregnated water, and the
liberation of nitrous oxide from it, it was im-
poffible to determine with the lead accuracy,
the quantities of products after refpiration.
About this time likewife, I often examined
the refiduum of nitrous oxide, after it had been
refpired in (ilk bags. In thefe experiments
when the gas had been breathed for along time,
a confidcrable diminution of it was obferved,
and the remainder extinguitlied flame and gave
a very flight diminution with nitrous gas. But
the great quantity of this remainder as well as
other phaenomcna, convinced me that though
the oiled lilk was apparently air tight when
( 390 )
dry, under flight preflure, yet during the adtion
of refpiration, the moid and warm gas expired^
penetrated through it, vvhilft conimon air en-
tered through the wetted furface.
To afcertain accurately, the changes efFc(3ed
in nitrous oxide by refpiration, I was obliged to
make ufeof the large mercurial airholder men-
tioned in Refearch I. of the capacity of 200
cubic inches. The upper cylinder of it was
accurately balanced fo as to be conftantly un-
der the preffiire of the atmofphere. To an
aperture in it, a flop cock having a very large
orifice was adapted, curved and flattened at its
upper extremity, fo as to form an air-tight
mouth-piece.
By accurately clofing the nofe, and bringing
the lips tight on the mouth-piece, after a few
trials I was able to breathe oxygene or com-
mon air in this machine for two minutes or two
minutes and half, without any other uneafy
feeling than that produced by the inclination of
the neck and cheft towards the cylinder. The
power of uniformly exbaufting the lungs and
( 391 )
fauces to the fame extent, I did not acquire till
after many experiments. At laft^ by preferving
exadlly the fame pofture after exhauflion of the
lungs before the infpiration of the gas to be ex-
perimented upon, and during its compleat expi-
ration, I found that I could always retain nearly
the fame quantity ofgas in the bronchial vefiels
and fauces ; the difference in the volume expi-
red at different times, never amounting to a
cubic inch and half.
By connedling the conduciing pipe of the
mercurial airholder, during the refpiration of
the gas, with a fmall trough of mergury by
means of a curved tube, it became a perfedl
and excellent breathing machine. Fqr by ex-
erting a certain prelTure on the airholding cylin-
der, it was eafy to throw a quantity of gas
after every infpiration or expiration, into
tubes filled with mercury flanding in the trough.
In thefe tubes it could be accurately analifed,
and thus the changes taking place at different
periods of the procefs afcertained.
Whenever I breathed pure nitrous oxide in the
mercurial airholder, after a compleat voluntary ex*
( 39'2 )
hauftion of my lungs, the plealurable delirium wal
very rapidly produced, andbeing obliged to ftoop
on the cylinder, the determination of blood to
my head from the increafed arterial adiion in
lefs than a minute became fo great, as often to
deprive me of voluntary power over the mufcles
of the mouth. Hence, I could never rely on
the accuracy of any experiment, in which the
•gas had been refpired for more than three
quarters of a minute.
I was able to refpire the gas with great accu-
rac/Yor more than half a minute ; it at firft,
rather increafing than diminifhing the power of
volition ; but even in this (hort time, very ftrong
fenfations were always produced, with fenfe of
fulnefs about the head, fomewhat alarming ; a
feeling which hardly ever occurs to me when the
gas is breathed in the natural pofture.
In all the numerous experiments that I made
on the refpiration of nitrous oxide in this way,
a very confidernble diminution of gas always
took place; and the diminution was generally
^pparentiy greater to the eye during the iirft
four or five infpirations.
( 303 )
The refidual gas of an experiment was alwayi^
examined in the following manner. After being
transferred through mercury into a graduated
cylinder, a fmall quantity of concentrated folu-
tion of cauftic potalh was introduced to it, and
fufFered to remain in conta6l with it for fome
hours ; the diminution was then noted, and the
quantity of gas abforbed by the potafh, judged
to be carbonic acid. To the remainder, twice
its bulk of pure water was admitted. After
agitation and reft . for four or five hours, the
abforption by this was noticed, and the gas ab-
forbed confidered as nitrous oxide. The refi-
dual unabforbable gas was mingled over water
with twice its bulk of nitrous gas ; and by this
means, its compolition, whether it confifted
wholly of nitrogene, or of nitrogene mingled
with fmall quantities of oxygene, afcertained*
From a number of experiments made at
different times on the rcfpiration of nitrous
oxide, I feleft the following as the moft accu-
rate.
( 394 )
E. 1. At temperature 54°, I breathed 102
cubic inches of nitrous oxide, which contained
near-^ common air, for aboiit half a minute,
feven infpirations and feven expirations being
made. After every expiration, an evident dimi-
nution of gas was perceived ; and when the lail
full expiration was made, it filled a fpace equal
to 62 cubic inche.s.
Thefe 62 cubic inches analifed, were found
to confift of
Carbonic acid . . 3,2
Nitrous oxide . . 29,0
Oxygene .... 4,1
Nitrogcne .... 25,7
62,0
Hence, accounting for the two cubic inches of
common air previoufly mingled with the nitrous
oxide, 71 cubic inches had difappeared in this
experiment.
In the laft refpirations, the quantity of gas
was fo much diminifhed, as to prevent the full
expanlion of the lungs 5 and hence the appa-
( 395 )
rent diminution was very much lefs after the
firft four infpirations.
E. 2. At temperature 47°, I breathed 182
cubic inches of nitrous oxide, mingled with 2^
cubicinchesofatmofphericairj which previoufly
exifted in the airholder, for near 40 feconds ;
having in this time made 8 refpirations. The
diminution after the firft full infpiration, ap-
peared to a by-ftander nearly uniform. When
the laft^compleat expiration was made, the gas
filled a fpace equal to 128 cubic inches, the
common temperature being reftored. Thefe
126 cubic inches analifed, were found to con-
fift of
Carbonic acid .... 5,25
Nitrous oxide .... 88,75
Oxygene 5,00
Nitrogene 29,00
Confequently, in this experiment, 93,25 cubic
inches of nitrous oxide had difappeared.
In each of thefe experiments, the cylinder
was covered v/ith condenfed watry vapor ex-
f 390 )
ailly in thei*ame manner as if common air had
been breathed in it. It ought to be oblcrved
that, E.-]. was made in the morning, four
hours and half after a moderate breakfaft ;
whereas, E. 2. was made but an hour and quar-
ter after a plentiful dinner ; at which near three-
fourths of a pint of table-beer had been drank.
From thefe experiments we learn, that nitrous
oxide is rapidly abforbed by the venous blood,
through the moift coats of the pulmonary veins.
But as after a compleat voluntary exhauftion
of the lungs, much relidual air mu(t remain in
the bronchial veffels and fauces, as appears from
their incapability of compleatly collapfing", it is
evident that the gas expired after every infpira-
tion of nitrous oxide mud be mingled with differ-
ent quantities of the rcfidual gas of the lungs;*
whilft after a complete expiration, much of the
unabforbcd nitrous oxide muft remain as refidual
gas in the lungs. Now when a complete expi-
* By lungs, I mean in this place, all the internal organs
of refpiration.
( 397 )
fation is made after the breathing of atmofpheric
air, it is evident that the refidual gasof the
lungs confifts of nitrogene,'^ mingled with fmall
portions of oxygene and earbonic acid. And
thefe are the only produces found after the ref-
piration of nitrous oxide.
To afcertain whether thefe producls were
partially produced, during the procefs of refpi-
ration, as I was -inclined to believe from the
experiments in the laft feifiion, or whether they
were wholly the refidual gafes of the lungs, I
found extremely difficult.
I at fu'Ct thought of bre;ithing nitrous oxide
immediately after my lungs had beei^ filled with
oxygene ; and to compare the producfls remain-
ing after the full expiration, with thofe pro-
duced after a full expiration of pure oxygene ;
but on the fuppofitioii that oxygene and nitrous
oxide, when applied together to the venous
blood, mufi: efFed changes in it dlPierent from
• Becaufe thefe products are formed during the refpira-
tion of common air.
t ^98 f
cither of them feparately, the idea was relin-
quifhed.
I attempted to infpire nitrous oxide, after hav-
ing made two infpirations and a complete exphv
ration of hydrogen e ; but in this experiment
the efFedls of the hydrogene were fo debilitating,
and the confequent ftimulation by the nitrous
oxide fo great, as to deprive me of fenfe.
After the firtl three infpirations, I loft all power
of ftanding, and fell on my back, carrying
in my lips the mouth-piece fcparated from the
cylinder, to the great alarm of Mr. PatrickDwyer,
who was noting the periods of infpiration.
Though experiments on fucceffive infpira-
tions of pure nitrous oxide might go far to
determine whether or no any nitrogene, car-
bonic acid and oxygene were produ6ls of
refpiration, yet I diftinclly faw that it was
impoflible in this way to afcertain their
quantities, fuppofing them produced, un-
lefs I could firft determine the capacity of my
lungs ; and the different proportions of the
gafes remaining in the bronchial veflels after a
( 399 )
compleat expiration, when atmofpheric air had
been refpircd.
In fome experiments (that I made on the ref-
piration of hydrogene, with a view to deternr)ine
whether carbonic acid was produced by the
combination of carbon loofely combined in
the venous blood, with the oxygene refpired, or
whether it was fimply give?! out as excrementi-
tious by this blood) I found, without however
being able to folve the problem I had propofed
to my lei fj that in the refpiration of pure hydro-
gene, little or no alteration of volume took
place ; and that the refidnal gas was mingled
with fome nitrogene, and a little oxygene and
carbonic acid.
From the comparifon of thefe fai^^s with thofe
noticed in the lad fe6iion and in R. III. Dlv: L
there was every reafon to fuppofe that hydro-
gene was not abforbed or altered when refpircd ;
but only "mingled with the refidual gafes of the
lungs. Hence, by making a full expiration of
atmofpheric air, and afterwards taking fix or
feven refpirations of hydrogene in the mercurial
( 400 )
airholder, and then making a compleat expira-
tion, I conjedlured that the refidual gas and
the hydrogene would be fo mingled, as that
nearly the fame proportions fhould remain in the
bronchial veflels, as in the airholder. By afcer-
taining thefe proportions and calculating from
them, I hoped to be able to afcertain with
tolerable exa^lnefs, the capacity of my fauces
and bronchia, as well as the compofition of the
gas remaining in them, after a complete expira-
tion of common air.
IV. Refpration of Hydrogene,
The hydrogene that I employed, was procu-
red from the decompofition of water by means
of clean iron filings and diluted fulphuric and
muriatic acids. It was breathed in the fame
manner as nitrous oxide, in the large mercurial
airholder.
After a compleat voluntary exhauftion of
my lungs in the ufual pofture, I found great
difficulty in breathing hydrogene for fo long
( 401 )
^s half a minute, fo as to make a compleat
Expiration of it. It produced uneafy feelings
in the chefi, momentary lofs of mufcular pow-
er, and fometimes a transient giddinefs.
In fome of the experiments that I made ; on
account of the giddinefs, the refults were ren-
dered inconclufive, by my rerhoving my mouth
from the mouth-piece after expiration, before
the affiftant could turn the ftopcock.
The purity of the hydrogene was afcertained
immediately before the experiment by the teft
df nitrous gas, and by detonation with oxygene
or atmofpheric air ; generally 12 meafures of
^tmofpheric air were fired with 4 of the hydro-
gene, and if the diminution was to ten or a little
inore, the gas was judged to be pure.
After the experiment, when the compleat
expiration had been made and the common
temperature reftored ; the volume of the gas
was noticed, and then a fmall quantity of it'
thrown into the mercurial apparatus by means
of the conducing tube, to be examined. The
carbonic acid was feparated by from it by means
.^
('402 )
of foli^tipn of potafh or flrontian ; the quantity of
oxygeiie it contained, was afcert^ned by means
of nitrous gas of known compofition ; the
fuperabundant nitrous gas was abforbed by
folution of muriate of iron ; and the proportions
of hydrogene and nitrogene in the remaining
gas, difcovered by inflammation with atmof-
pheric air or oxygene in the detonating tube
by the elecSric fpark.
a. The two following experiments made upon
quantities of hydrogene, equal to thofe of the ni-
trous oxide refpired in the experiments in the laft
feflion, are given as the mod accurate of five.
E. 1. I refpired at 59° 102 cubic inches of
hydrogene apparently pure, for rather lefs than
half a minute, making in this time feven quick
refpirations.
After the complete expiration, when the
common temperature was reftored, the gas
occupied a fpace' equal to 103 cubic inches
nearly. Thefe analifed were found to confift
of
%. .i
rfi^H^
( 403 )
Carbonic acid . . 4,0
Oxygene 3,7
Nitrogene .... 17,3
Hydrogene .... 78,0
103,0
Now as in this experiment, the gas was increafed
in bulk only a cubic inch ; fuppofing that after
the compleat expiration the gas in the lungs,
bronchia and fauces was of nearly fimilar com-
pofition with that in the airholder, and that no
hydrogene had been abforbed by the blood, it
would follow that 24 cubic inches of hydrogene
remained in the internal organs of refpiration,
and confequently, by the rule of proportion,
about 7,8 of the mixed refidual gas of the com-
mon air. And then the whole quantity of refi-
dual gas of the lungs, fuppofing the temperature
59°, would have been 31,8 cubic inches ; but as
its temperature was nearly that of the internal
parts of the body, 98°, it muft have filled a
greater fpace ; calculating from the experiments
')
( 404 )
of Guyton and Vernois,* about 37, 5[ cubic
inches.
From the increafe of volume, it would appear
that a minute quantity of gas had been gene-
rated during the refpiration, and this was, as
we fhall fee hereafter, moft probably carbonic
acid.§ Likewife there is reafon to fuppofe, that
a little of the refidual oxygene maft have been
abforbed. Making allowances for thofe circum-
flances, it would follow, that the 37,5 cubic
inches of gas remaining in my lungs, after a
Gompleat expiration of atmofpheric air at animaK
heat 98°, equal to 31,8 cubic inches at bQ"",
were compofed of
Nitrogene ....
2i,g
Carbonic acid . ,
4,9
Oxygene ....
5,0
31,8
■* Annales de Chimie, vol. 1, page 279.
f This is only an imperfe6t approximation j the ratio
of the increafe of expanfibility of gafes to the increafe of
temperature, has not yet been afcertained. It is probable
that the expanfibility of gafes is altered by their mixture.
§ For there is no reafon to fuppofe the produ6lion of nitrogene.
( 405 )
E. 2. I rcfpired for near a half a minute in
the mercurial airholder at 6l°, 182 cubic in-
ches of hydrogene ; having made during this
time, fix long infpirations. After the laft ex-
piration, the gas filled a fpace nearly equal to
184 cubic inches, and analifed, was found to
con lift of
Carbonic acid .... 4,8
Oxygene 4,6
Nitrogene 21,0
Hydrogene 153,6
184.
Now in this experiment, reafoning in the fame
manner as before, 28,4 cubic inches of hydro-
gene muft have remained in the lungs, and
likevvife 5,5 of the atmofpheric refidual gas.
Confequently, the whole refidual gas was nearly
equal to 34 cubic inches at 6 Jo, which at 98^
would become about 40,4 cubic inches. And
reafoning as before, it would appear from this
experiment, that the quantity of gas remaining
in my lungs after a compleat voluntary refpira-
( 406 )
tion, equalled at 98, about 40 cubic inches,
and at 61"^, 34 nearly : making the neceflary
corredlions ; that after common air had been
breathed, thefe 34 cubic inches confifted of
Carbonic acid .... 4,1
Oxygene 5,5
Nitrogene ...... 24,4
h. It would have been poflible to prove the truth
of the poftulate on which the experiments were
founded, by refpiring common air or oxygene
after the compleat expiration of the hydrogene,
for the fame time as the hydrogene was ref-
pired and in equal quantities.
For if portions of hydrogene were found in
the airholder equal to thofe of the refidual gafes
in the two experiments, it would prove that a
uniform mixture of refidual gas with the gas
infpired, was produced by the refpiration. That
this mixture muft have taken place, appeared,
however, fo evident from analogous fads, that
I judged the experimental proof unnecefiary.
Indeed, as mod gafes, though of different fpe-
cific gravities, when brought in contadl with each
{407 )
other, aflume fome fort of union, it is more
than probable, that gas infpired into the lungs,
from being placed in contact with the refidual
gas on fuch an extenfive furface, muft inftantly
mingle with it. Hence, poffibly one deep in-
fpiration and compleat expiration of the whole
of a quantity of hydrogene, will be fufficient to
determine the capacity of the lungs after com-
pleat voluntary exhauftion, and the nature of
the refidual air.
That two infpirations are fufficient, appears
probable from the following experiment.
E. 3. After a compleat voluntary expiration
of common air, I made two deep infpirations of
141 cubic inches of hydrogene. After the
compleat expiration, they filled a fpace equal
to rather more than 142 cubic inches, and
analifed, were found to confift of
Carbonic acid .... 3,1
Oxygene 4,5
Nitrogene 18,8
Hydrogene 115,6
142.
j:-J»^'-i
( 408 )
Now calculating on the exhaufted capacity of
my lungs froni this experiment, fuppofing uni-
form mixture, they would contain after expir
ration of common air, about 30,7 cubic inches
at 58°, equal to 36 at 98°, compofed of about
Nitrogene .... 20,9
Oxygene .... 5,8
Carbonic acid . . 4,0
30,7
One fhould fuppofe a priori that in this experi-
ment much lefs of the refidual oxygene of the
lungs muft have been abforbed, than in Expts.
1 and 2 ; yet there is no very marked difference
in the portions evolved. That a tolerably accu-
rate mixture took place, appears from the quan-
tity of nitrogene. The fmaller quantity of
carbonic acid is an evidence in favour of its
evolution from the venous blood.
c. It is reafonable to fuppofe that the prefTure
upon the refidual gas of the exhaufled lungs,
mufl be nearly equal to that of the atmofphere.
But as aqueous vapour is perpetually given out
( 409 )
by the exhalents, and perhaps evolved from the
moift coats of the pulmonary veflels, it is likely
that the relidual gas is not only fully faturated
with moifture at 98^, but likewife impregnated
with uncombined vapor ; and hence its volume
enlarged beyond the increment of expanfion
6f temperature.
Confidering all thefc circumftances, and cal-
culating from the mean of the three experi-
ments on the compofition of the refidual gas,
I concluded,
lit. That the exhauftcd capacity of my lungs
was equal to about 41 cubic inches.
2dly. That the gas contained in my bron-
chial vefTels and fauces^ after a compleat refpi-
ration of atmofpheric air, was equal to about
32 cubic inches, its temperature being reduced
to 55°.
3dly. That the(e 32 cubic inches were com-
pofed of about
Nitrogene . . 23,0
Carbonic acid . . 4^1
Oxygene . . . 4,9
(410 )
d. In many experiments made In the mercurial
airholder on the capacity of my lungs under
different circumftances, I found that I threw
out of my lungs by a full forced expiration at
temperatures from 58° to 62°
cab. in. cub. in;,
Afterafull voluntary infpiration^ from 1 89 to Igl
After a natural infpiration, from . . 78 to 79
Aftera natural expiration, from .. 67 to 6$
So that making the corrections for temperature,
it would appear, that my lungs in a ftate of volun-
tary infpiration, contained about 254 cubic in-
ches ; in a ftate of natural infpiration about 135 ;
in a ftate of natural expiration, about 118 ; and
in a ftate of forced expiration 41.*
As the exhaufted capacity as well as imple-
ted capacity of the internal organs of refpiration
muft be different in different individuals, ac-
cording as the forms and fize of their thorax.
* This capacity is moft probably below the medium, raj
chcft is narrow, raeafuring in circumference, but 29 inches,
and my neck rather long and llender.
( 411 )
fauces, and broncbia are difFerent, it would b«
almoft ufelefs to endeavour to afcertain a firand-
ard capacity. It is however probable, that a
ratio exifts between the quantities of air infpi*
red in the natural and forced infpiration, tbofe
expired in the natural and forced expiration,
and the whole capacity of the lungs. If this
ratio were afcertained, a fingle experiment
on the natural infpiration and expiration of
common air, would enable us to afcertain the
quantity of refidual gas in the lungs of any
individual after a compleat forced expiration."^
V. Additional ohjervations and experiments
on tic Refpiration of Nitrous Oxide,
a. Having thus afcertained the capacity of my
lungs, and the compofition of the refidual gas
of expiration, I proceeded to reafon concerning
* Dr. Goodwyn In his excellent work on the connexion
of life with refpiration, has detailed fome experiments on
the capacity of the lungs after natural expiration. He
makes the medium capacity about 109 cubic inches, which
agrees very well with my elUmation. — page 27.
f 411 )
the experiments in fe6lion III, on the refpiration
of nitrous oxide.
In Exp. I. nearly 100 cubic inches of nitrous
oxide, making the corredlions on account of
the common air, were refpired for half a minute.
In this time, they were reduced to 62 cubic in-
ches, which confided of 3,2 carbonic acid, 29
nitrous oxide, 4,1 oxygenc, and 25,7 nitrogene.
But, as appears from the lad fe6lion, there
exifted in the lungs before the infpiration of the
nitrous oxide, about 32 cubic inches of gas,
confiding of 23 nitrogene, 4, J carbonic acid,
and 4,9 oxygene, temperature being reduced to
59*^. This gas mud have been perfedlly ming-
led with the nitrous oxide during the experi-
menl; and confequently, the refidual gas in the
lungs after the experiment, was of the fame
compofition as that in the airholder.
Suppofing it as before, to be about 32 cubic
inches : from the rule of proportion, they will
be compofed of
Nitrous oxide . . 14,7
Nitrogene 13,3
( 413 )
Carbonic acid . . 1,9
Oxygene 2,1
And the whole quantity of gas in the l^ngs and
the airholder, fuppofing the temperature 50°,
will equal 94 cubic inches, which are compofed
of
Nitrous oxide- . . 43,7
Nitrogene ...... 39,0
Carbonic acid . . 5, 2
Oxygene 6, 1
94
But before the experiment, the gas in the lungs
and airholder equalled 134 cubic inches, and
thefe, reckoning for the common air, were
compofed of
Nitrous oxide . . 100
Nitrogene, .... 24,3
Carbonic acid . . 4,1
Oxygene .... 5,6
Hence, it appears, that, 56,3 cubic, inches of
nitrous oxide were abforbed in this experiment,
and 13,7 of nitrogene produced, either by evo-
lution from the bloody or decompofition of the
-^~^—^~~
( 414 )
nitrous oxide. The quantities of carbonic acid
and oxygene approach fo near to thofe exifting
after the refpiration of hydrogene, that there is
every reafon to believe that no portion of them
was produced in confequence of the abforption,
or decompofition of the nitrous oxide.
h. In Exp. 2, calculating in the fame manner,
before the firft infpiration, a quantity of gas
equal to 21 6^5 cubic inches at 47°, exifted in
the lungs and airholder, and thefe 216,5 cubic
inches were compofed of
Nitrous oxide, .... 182,0
Nitrogene 24,9
Carbonic acid .... 4,1
Oxygene 5^5
2l6,5
After the compleat expiration, l6o cubic in-
ches remained in the lungs and airholder, which
was compofed of
Nitrous oxide . . 1 10,6
Nitrogene 36,3
Carbonic acid 6,8
Oxygene ..,*..., 6,a
( 435 )
Henqe, it appears, that 71,4 cubic inches of
nitrous oxide were abforbed in this experiment,
and about 12 of nitrogene produced. The
quantity of carbonic acid and oxygene is rather
greater than that which exifted in the experi-
ments on hydrogenc.
c. From thefe eftimationSj I learned that a
fmall quantity of nitrogene was produced daring
the abforption of nitrous oxide in refpiration.
It remained to determine, whether this nitro-
gene owed its production to evolution from the
blood, or to the decompofitlon of a portion of
the nitrous oxide.
Analogical evidences were not in favour of the
hypothefisof decompofition. It was difficult to
fuppofe that a body requiring the temperature of
ignition for its decompofition by the mod inflam-
mable bodies, fhould be partially abforbed and
partially decompounded at 98°, by a fluid ap-
parently pofTefTed of uniform attractions.
It was more eafy to believe, that from the
immenfe quantity of nitrogene taken into the
blood in nitrous oxide ; the fyftem foon became
-y
( 416 )
bvercharged with this principle/ which not beirrg
wholly expended in new combinations during
living adlion, was liberated in the aeriform Itate'
by the exhalents^ or through the moift coats of
the veins.
Now if the laft rationale were true, it vvould-
follow, that the quantity of nitrogene produced
in refpiration, ought to be increafed in propor-
tion as a greater quantity of nitrous oxide
entered into combination with the blood.
d. To afcertain whether this was the cafe, I
made after full voluntary exhauftion of my
lungs, one full voluntary infpiration and expi-
ration of 108 cubic inches of nitrous oxide.
After this, it filled a fpace nearly equal to 99
cubic inches. The quantities of carbonic acid
and oxygene in thefe were not determined ; but
by the teft of abforption by water, they appeared
to contain only 18 nitrogene; which is very
little more than fhould have been given from
the relidual gas of the lungs.
In a fecond experiment, I made two refpira^
tions of 108 cubic inches of nitrous oi de
( 417 )
Dearly pure. The diminution was to 95. On
analyfing thefe Q5,_ I found to my great furprife^
that they contained only 17 nitrogene. Hence,
1 could not bat fufpecl fpmc fource of error in
the procefs.
I now introduced into a ftrong new filk
bag, the fides of which were in perfe6l contacS,
about 8 quarts of nitrous oxide. From the
mode of introduction, this nitrous oxide muft
have been mingled with a little common air,
not however fufficient to difturb the refults.
I then adapted a cork cemented to a long
curved tube to my right noftril ; the tube was
made to communicate with the water apparatus;
and the left noftril being accurately clofed, and
the mouth-piece of the filk bag tightly adapted
to the lips, I made a full expiration of the com-
mon air of my lungs, infpired nitrous oxide fi'om
the bag, and by carefully ciofing the mouth-
piece with my tongue, expired it through
the curved tube into the v/ater apparatus. In
this way, I made nine refpirations of nitrous
oxide. The expired gas of the firft refpiration
Cc.
( 418 )
was not preferved ; but part of the gas of the
fecond, third, fifth, feventh and ninth, were
caught in feperatc graduated cylinders. The
fecond, analifed by abforption, confifted of
about 29 ftbforbable gas, which inuft have been
chiefly nitrous oxide ; and 17 unabforbable gas,
which muft have been chiefly nitrogene; and the
third of 2'2 abforbable gas, and 8' unabforbable.
The fifth was compofed of 27 to 6 ; the feventh
of 23 to 7, and the ninth of 26 to ] 1.
e. Though the refults of thefe experiments
were not fo conclufive as could bewiflied; yet,
comparing them with thofe of the experiments in
fe6lion III. it feemed reafonable to conclude,
that the produ6iion of nitrogene was increaled,
in proportion as the blood became more fully
impregnated with nitrous oxide.
From this conclufion, compared with the phag-
nomenon noticed in fedtion 2, and in Div. I.
fedlion 4, I am induced to believe that the pro-
dudlion of nitrogene during the refpiration of
nitrous oxide, is not owing to the decompofi-
tion of part of the nitrous oxide, in the
Mi
( 419 )
aeriform ft ate immediately by the attradlion of
the red particles of venous blood for its oxygene ;
but that it is rather owing to a new arrangenient
produced in the priiiciples of the impregnated
bloodj during circulation ; from which, becoming
fuperfaturated with nitrogene, it gives it out
through the moid coats of the vefTels.
For if any portion of nitrous oxide were de-
compofed immediately by the red particles of
the blood, one fhould conjedure, that the quan-
tity of nitrogene produced, ought to be greater
during the firft infpirations, before thefe particles
became fully combined with condenfed oxygene.
If on the contrary, the whole of the nitrogene
and oxygene of the nitrous oxide were both
combined with the blood, and carried through the
pulmonary veins and left chamber of the heart to
the arteries ; then, fuppofing the oxygene chiefly
expended in living a^ion, wbilft the nitrogen©
was only partially confumed in new combina-
tions, it would follow, that the venous blood of
animals made to breathe nitrous oxide, hyper-
faturated with nitrogene, muft be different from
( 4^0 )
comnpion veilous blood ; and this we have resf-
tfbn to. believe from the phaenomena in Div. I.
fedlioa 4, is adlually the cafe.
/, Befides the nitrogene generated during
the refpiration of nitrous oxide, we have noticed
the evolution of other produ<Ss, carbonic acid/*
and water.
Now as nearly equal quantities of carbonic
acid are produced, whether hydrogene or ni-
trous oxide is refpired, provided the procefs h
carried on for the fame time ; there is every
reafon to believe, as we have faid before, that no
part of the carbonic acid produced, is generated
from the immediate decompofition of nitrous
oxide by carbon exifting in the blood.
Confequently, in thefe experiments, it mui^
be either evolved from the venous blood ; or
formed, by the flow combination of the oxygene
of the refidtlal air of refpiration with the char-
coal of the blood.
* The oxygene as we Iiave before noticed, moft proba-
bly wholly exiflfd in the refidual gas.
( 421 )
But if it was produced by the decompofition
of refidual atmofpheric air, it would follow^
that its volume muli be much lefs than that of
the oxygene of the refidual air, which had
difappeared ; for fome of this oxygene muft
have been abforhed by the blood, and during
the converfion of oxygene into carbonic acid by
charcoal, a flight diminution of volume is pro-
duced.
In the experiments when nitrous oxide and
hydrogene were refpired for about half a minute,
the medium quantity of carbonic acid produced,
was 5,6 cubic inches nearly.
Now we will affume, that the quantity of
carbonic acid produced, is in the ratio of the
oxygene diminifhed ; and there is every reafon
to believe, that in the expiration of atmofphe-
ric air, the expired air and the refidual air are
nearly of the fame compofition.
Hence, no more carbonic acid can remain
in the lungs or be produced from the refidual
gas after the compleat expiration of common
air, than that which can be generated frorn a
^•■--v
' ( 422 )
volume of atmofpheric air equal to the refidual
gas of the lungs.
The refidual gas of the lungs, after compleat
expiration, equals at 55©, 32 cubic inches, and
32 cubic inches of common air contain 8.6
cubic inches of oxygene.
But in the experiments on the refpiration of
hydrogene, not only 5.6 cubic inches of car-
bonic acid were produced, but more than 4 of
refidual oxygene remained unabfbrbed.
Hence it appears impoflSble that all the car-
bonic acid evolved from the lungs during the
refpiration of nitrous oxide or hydrogene could
have been produced by the combination of char«
coal in the venous blood with refidual atmof-
pheric oxygene : there is confequently every
reafon to believe that it is wholly or partially li-
berated from the venous blood through the moid
coats of the vcfiels.
g. The water carried out of the lungs in fo-
lution by the expired gas of nitrous oxide, could
neither have been wholly or partially formed
by the decompofition of nitrous oxide. The
( 423 )
coats of the ve^fels in the lungs, and indeed in
the whole internal furface of the body, are
always covered with moifture, and the folution
of part of this moifture by the infpired heated
gas, and its depofition by the expired gas, are
fufficient caufes for the appearance of the
phaenomenon.
There are no reafons for fuppoiing that any
of the refidual atmofpheric oxygene is imme-
diately combined with fixed or nafcent hydro-
gene, or hydrocarbonate, in the venous blood at
98°, by flow combuftion, and confequently
none for fuppofing that water is immediately
formed in refpiration.
The evolution of water from the veflels in
the lungs, is almoft certain from numerous
analogies.
h. As from the experiments in fe<ftion II. it
appeared that nitrous oxide was capable of being
combined with oxygenated blood, and vice verfa,
blood impregnated with nitrous oxide capable
of oxygenation ; I wascuriousto afcertain what
changes would be efFe<5led in nitrous oxide when
( 424 )
it was refpiredj, mingled with atmofphe-
rlc air or oxygene. For this purpofe, with-
out making a very delicate experiment^ I breath-
ed in the large mercurial airholder about ] 12
cubic inches of nitrous oxide, mingled with
44 of common air, for near half a minute, in
the ufual mode. The gas, after expiration, fil-
led a fpace nearly equal to IIQ. I did not
exa6lly afcertain the compolition of the refidual
gas ; it fupported flame rather better than com-
mon air, and after the nitrous oxide was ah-
forbed, gave much lefs diminution with nitrous
gas than atmofpheric air.
i. I breathed a mixture of four quarts of
nitrous oxide with three quarts of hydrogene,
in a dry filk bag, for near a minute ; an evi-
dent diminution was produced ; but on account
of the mode of experimenting it was impoflible
to determine the quantity of nitrous oxide ab-
forbed, or the exa6l nature of the products.
When a taper was introduced into a little of the
refidual gas, it inflamed with a very feeble ex-
plofion. Now a mixture of 4 parts nitrous ox-
( 425 )
ide and 3 hydrogene, detonates when inflamed
with very great violence.
k. Nitrous oxide can be refpired without
danger by the human animal for a much longer
time than that required for the death of the
fmaller quadrupeds in it.
I have breathed it two or three timevS in a
confiderable ilate of purity, in a dry filk bag,
for four minutes and quarter and four minutes
and half: fome difeafed individuals have refpi-
red it for upwardsof five minutes.
In the infancy of my experiments, from gene-
ral appearances, I thought that the proportion of
nitrous oxide abforbed in refpiration was greater
in the firftinfpirationsthanthelafl; but this I have
fince found to be amiftake. In ihelafl refpirations
the apparent abforption is indeed lefs ; but this is
on account of the increafed evolution of nitro*
gene from the blood. When nitrous oxide is
refpired for a long time, the laft infpirations arc
always fuller and quicker than the firft ; but
the confumption by the fame individual is nearly
in the ratio of the time of refpiration. Three
( 426 )
quarts i. c. about 174 cubic inches, areconfumecl
fo as to be unfit for refpiration, by an healthy
individual with lungs of moderate capacity, in
about a minute and quarter ; fix quarts, or 348
cubic inches, lafl: generally for two minutes and
half or two minutes and three quarters ; eight
quarts, or 464 cubic inches, for more than
three minutes and half; and twelve, or 696
cubic inches, for nearly five.
The quantities of nitrous oxide abforbed by
the fame individual, will, as there is every rea-
fon to fuppofe, be different under different
circumftances, and will probably be governed
in fome meafure by the (late of the health. It
is reafonable to fuppofe, that the velocity of the
circulation muft have a confiderable influence
on the abforption of nitrous oxide ; probably in
proportion as it is greater a larger quantity of
gas will be conlumed in equal times.
I am inclined from two or three experiments,
to believe that nitrous oxide is abforbed more
rapidly after hearty meals or during flimulation
from wine or fpirits, than at other times. As
( 427 )
its abforption- appears to depend on a fimple
folution in the venous blood ; probably diminu-
tion of temperature will increafe its capability
of being abforbed.
/. The quantities of nitrous oxide abforbed by
different individuals, will probably be governed
in fome meafure by the fize of their lungs and
the furface of the blood vefTels, all other cir-
cumftances being the fame.
From the obfervations that I have been able
to make on the abforption of nitrous oxide, as
compared with the capacity of the lungs, the
range of the confumption of different individu-
als does not extend to more than a pint, or 30
cubic inches at the maximum dofe.
We may therefore conclude, that the medium
confumption of nitrous oxide by the refpiratioil
of different individuals, is not far from two
cubic inches, or about a grain every fecond,
or 120 cubic inches, or 6o grains every minute.
m. When nitrous oxide is breathed in tight
filk bags, towards the end of the experiment as
the internal furface becomes moid, as I have
before n^entioned, a certain quantity of CO.
rafidualgasofth. '' "''™"^ ^'^^e. The
gas of the common air th^ „;*
hardly ever amo„ at; ^^'"°'"'^^-^-'^'
-hairorthe J„:!V,V't^^--'*'^
''ed. There ,s confequenfjy, a perfedl
Propnefy in fucceffively infpirino- /
*he whole of a ^iven ^ ''P'""^
_ o a g.ven quantity of nitrous oxide
tdl It ,s nearJy confumed. Jn the r.r • .•
»« an , ™e re , „„„„„r ,.,„„,,■
'l-»P.nceof,..r„Ma„..,-3„f,„p„„,„,f
( 429 )
VI. On the refpiration of jitmofpheric Air.
Having thus afcertained the abforption of
nitrous oxide in refpiration, and the evolution
of nitrogene and carbonic acid from the lungs
during its abforption : confidering atmofpheric
air as a compound in which principles identi-
cal with thofe in nitrous oxide exifted, though
in different quantities and loofer combination,
I was anxious to compare the changes efFetfled
in this gas by refpiration, with thofe produced
in nitrous oxide and oxygene ; particularly as
they are connedled with the health and life of
animals.
The ingenious experiments of Lavbifier and
Goodwyn, prove the confumption of oxygene
in refpiration, and the prod u(Si ion of carbonic
acid. From many experiments on the refpira-
tion of common air. Dr. Prieftley fufpeded that
a certain portion of nitrogene, as well as oxygene,
wasabforbed by the venous blood.
( 430 )
h. In the following experiments on the refpi"
ration of atmofpheric air in the mercurial air-
holder ; the compofition of the gas before infpi-
ration and after expiration, was afcertained in
the following manner.
Forty meafures of it were agitated over mercury
in folution of cauftic potafh^^and fufFered to remain
in contadl with it for two or three hours. The
diminution was noted, and the gas abforbed
Judged to be carbonic acid. Twenty meafures
of the gas, freed from carbonic acid, were ming-
led with thirty of nitrous gas, in a tube of ,5
inches diameter ; they were not agitated,^ but
fufFered to reft for an hour or an hour and half,
when the volume occupied by them was noticed :
and 50 — m the volume occupied, divided
by 3 confidered as the oxygefie x^ and 20 — x
confidered as the nitrogene.
* When they are agitated; a greater proportion of nitrous
gas is abforbed, condenfed in the nitric acid by the water j
and to find the oxygene^ 50 — m 50 — m
X ~ or ■
3,4 3,5
* ( 431 )
c. To afcertain the changes efFefled in at-
mofpheric air by fingle infpirations,
I made, after a compleat voluntary exhauftion of
my lungSj at temperature 61°, one infpiration and
expiration of 141 cubic inches of atmofpheric
air. After expiration, they filled a fpace equal
to 139 cubic inches nearly. Thefe 139 cubic
inches analifed were found to confift of
Nitrogene ....
101
Oxygene . . . .
32
Carbonic acid .
. 5
The 141 cubic inches before infpiration,
were compofed of 103 nitrogene, 1 carbonic |
acid and 37 oxygene. The time taken to per- ■
form the infpiration and full expiration, was J
nearly a quarter of a minute.
I repeated this experiment feven or eight
times, and the quantity of oxygene abforbed
was generally from 5 to 6 cubic inches, the
carbonic acid formed from 5 to 5,5, and the ^^
quantity of nitrogene apparently diminiflied by
from 1 to 3 cubic inches.
( 132 )
E. 2. i made, after a voluntary expirafionr of
common air, one infpiration and full expiration?
of 100 cubic inches of atmofpheric air. It was
diminifhed nearly to QS^ or 99 cubic inches,
^nd analifed, was found to coniiit oi
Nitrogene , . 713?
Oxygen e .... 22.5
Carbonic acid . . 4,5
This experiment 1 likewife repeated four or five
times, with very little difference of refult, and
there always feemed to be a fmall diminution of
nitrogene. I made no corredtions on account
of the refidual air of the lungs in thefe pro-
cefles, becaufe there was every reafon to lup-
pofe that it was always of fimilar compofition.
c. Before I could afcertain whether fimilar
changes were efl^edled in atmofpheric air, by
natural infpirations as by forced ones, I was
obliged to pradlife refpiration in the mercurial
airholder, by fufFering the conducing tube to
communicate with the atmofphere till I had
attained the power of breathing in it naturally,
without labor or attention ; I then found by a
— ««MMm.
( 449 )
IX. Obfervations on the rejpration of Nitrous
Oxide,
The experiments in the firft Divilion of this
Refearch, prove that nitrous oxide when refpired
by animals, produces peculiar changes in their
blood and in their organs, firft coanedled with
increafed living aflion ; but terminating in
death.
From the experiments in this Divifion, it
appears, that nitrous oxide is rapidly abforbed
by the circulating venous blood, and of courfe
its condenfed oxygene and nitrogene diflributed
in the blood over the whole of the fyftem.
Concerning the changes cfFedled in the prin-
ciples of the impregnated blood during circula-
tion and its adiion upon the nervous andmufcular
fibre ; it is ufelefs to reafon in the prefent ftalc
of our k no Vv ledge.
It would be eaiy to form theories referring
the a6lion of blood impregnated with nitrous
oxide, to its power of tuppl ving the nervous and
mufcular fibre with fuch proportions of condcn-
Ee
( 450 )
fed nitrogene, oxygene and light or etherial
fluid, as enabled them more rapidly to pafs
through thofe changes which conftitute their
life : but fuch theories would be only collections
of terms derived from known phaenomena and
npplied by loofe analogies of language to un-
known things.
We are unacquainted with the compofition
of dead organifed matter ; and new inftruments
of experiment and new modes of refearch muft
be found, before we can afcertain even our
capabilities of difcovering the laws of life.
-»:::::2:
RESEARCH IV.
RELATING TO THE
EFFECTS PRODUCED BY THE RESPIRATION
NITROUS OXIDE
UPON DIFFERENT
INDIVIDUALS,
RESEARCH IV.
RELATING TO
THE EFFECTS
PRODUCED BY THE
kESPIRATION OF NITROUS OXIDE.
DIVISION I.
HISTORY of the DlSCOVERT.^EffeBs produced &>
ibe RESPIRATION of different GASES.
-TJL SHORT time after I began the Audy of*
Chemiftry, in March IJQS, my attention was
diredled to the dephlogifticated nitrous gas of*
Prieftley, by Dr. Mitchiirs Theory of Contagion *
The fallacy of this Theory was foon demori-
flrated, by a few coarfe experiments made on
fmall quantities of the gas procured from zinc
* Dr. Mitchill attempted to prove from fome phaenome-
na conneded with contagious difeafes, that dephlogifticated
tiitrous gas which he called oxide of fepton, was the prin-
ciple of contagion, and capable of producing the mod terri-
ble effeds when refpired by animals in the minuteft quantities
or even when applied to the Ikin or mufeular fibre.
( 454 )
and diluted nitrous acid. Wounds were expof
fed to its adlion, the bodies of animals were
immerfed in it without injury ; and I breathed
it mingled in fmall quantities with common air,
without remarkable efFedls. An inability to
procure it in fufficient quantities, prevented me
at this time, from purfuing the experiments to
any greater extent. I communicated an ac-
count of them to Dr. Beddoes.
In 1799, my fituation in the Medical Pneu-
matic Inftitution, made it my duty to invefy^
gate the phyfiological efFedls of the aeriforqj
fluids, the properties of which prefented ^
chance of ufeful agency. At this period I re-
commenced the inveftlgation.
A confiderable time elapfed before I was
able to procure the gas in a ftate of purity, and
my firft experiments were made on the mixtures
of nitrous oxide, nitrogen e and nitrous gas,
which are produced during metallic folutions.
*In the beginning of March, I prepared a large
quantity of impure nitrous oxide from the ni-
trous folution of zinc. Of this I often breathed
( 455 )
the quantities of a quart and two quarts gene-
rally mingled with more than equal parts of
. oxygene or common air. In the mod decifivie
of thofe trials, its efFeds appeared to be depref-
ling, and I imagined that it produced a ten-
dency to fainting : the pulle was certainly
rendered flower under its operation.
At this time, Mr. Southey refpired it in an
highly diluted ftate ; it occafioneda flight degree
ofgiddinefs, and confiderably diminifhed the
quicknefs of his pulfe.
Mr. C. Coates likewife refpired it highly dilu-
ted, with fimilar efFeds.
In April, I obtained nitrous oxide in a ftatc
of purity, and afcertained many of its chemical
properties. Refle<5lions upon thefe properties
and upon the former trials, made me refoive to
endeavour to infpire it in its pure form, for I
/aw no other way in which its refpirability, or
powers could be determined*
.}{rf 'it.l ^^';:J iil;l .4; OhH I; ^
* 1 did not attempt to experiment upon animals^ becaufe
they die nearly in eqnal times in non-rcfpirable gafcs, and
gafes incapable of fupporting life aaJ pofTeilcd of no
action on the venous blood.
( 456 )
I was aware of the danger of this experiments
It certainly would never have been made if the
hypothecs of Dr. Mitchill had in the leat^ influ-
enced my mind. I thought that the effeds
might be poffiblydeprefling and painful, but there
were many reafons which induced me to believe
that a fingle infpiration of a gas apparently
pofTefling no immediate a6iion on the irritable
fibre, could neither deftroy or materially injure
the powers of life.
On April ] 1th, I made the firft infpiration of
pure nitrous oxide ; it patfed through the
bi'onchia without Simulating the glottis, and
produced no UHcafy feeling in the lungs.
The refult of this experiment, proved that
the gas was refpirable, and induced me to be-
lieve that a farther trial of its efFeds might be
made without danger.
On April ]6th. Dr. Kinglake being accidentally
prefent, I breathed three quarts of nitrous ox-
ide from and into a filk bag for more than half
a minute, without previoufly clofing my nofe or
exhaufting my lungs.
( 457 )
The firft infpirations occafioned a flight degree
of giddinefs. This was fucceeded by an un-
common fenfe of fulnefs of the head, accom-
panied with lofs of diftinft fenfation and volun-
tary power, a feeling analogous to that produced
in the firft ftage of intoxication ; but unattended
by pleafurable fenfation. Dr. Kinglake, who felt
my pulfe, informed me that it was rendered
quicker and fuller.
This trial did not fatisfy me with regarcjl
to its powers ; comparing it with the former
ones I was unable to determine whether the
operation was flimulant or depreffing.
I communicated the refult to Dr. Beddoes,
and on April the 17 th, he was prefent, when
the following experiment was made.
Having previoufly clofcd my noitrils and
exhaufted my lungs, I breathed four quarts of
nitrous oxide from and into a filk bag. The
firft feelings were fimilar to thofe produced in
the laft experiment ; but in lefs than half a
minute, the refpiration being continued, they
diminifhed gradually, and were fucceeded by a
( 458 )
fenftftion analogous to gentle preffiire on all the
mufcles, attended by an highly pleafurable
thrilling, particularly in the cheft and the ex-
tremities. The objefls around me became
dazzling and my hearing more acute. Towards
the laft infpirations, the thrilling increafed,
the fenfe of mufcular power became greater,
and at laft an irrefiftible propenfity to a6lion was
indulged in ; I recollect: but indiftindlly what
Followed ; I know that my motions were vari-
ous and violent.
Thefe efFeds very foon ceafed after refpiration.
In ten minutes, I had recovered my natural ftate
of mind. The thrilling in the extremities,
continued longer than the other fenfations.*
This experiment was made in the morning;
no languor or exhauftion was confequent, my
feelings throughout the day were as ufual,
tmd I paflTed the night in undifturbed repofe,
'f-' Dr. Beddoes has given fome account of this experiment,
in hjs Notice of fppie obfervations made at the Medical
Pneumatic Inftitution. It was noticed in Mf. Nicholfen's
Thil. Journal for May 1 1^^.
( 459 )
The next morning the recolledlions of the
efFefls of the gas were very indiftindl, and had
not remarks written immediately after the expe-
riment recalled them to my mind, I fhould
have eyen doubted of their reality. I was vvil-
ling indeed to attribute fomc of the ilrong emo-
tion to the enthufiafm, which I fuppofed muft
have been neceflarily conne6led with the per-
ception of agreei^ble feelings, when I was pre-
pared to experience painful ftnfations. Two
experiments however, made in the courfe of
this-day, with fceptilm, convinced me that the
.efFedls were folely owing to the fpecific opera^
tion of the gas.
In each of them I breathed five quarts of
nitrous oxide for rather a longer time than
before. The fcnfations produced were ti miliar,
perhaps not quite fo pleafurable ; the mufculap
motions were much lefs violent. .f.:'^' ■
Having thus afcertained the powers of the
gas, I made many experiments to afcertain the
length of time for which it might be breathed
with fafety, its effecls on the puife, and its
( 46o )
general effects on the health when often re(^-
pired.
I found that I could breathe nine quarts of
nitrous oxide for three minutes, and twelve
quarts for rather more than four. I could
never breathe it in any quantity, fo long as five
minutes. Whenever its operation was carried
to the higheft extent, the pleafurable thrilling
at its height about the middle of the experiment,
gradually diminiOied, the fenfe of prefTure on
the mufcles was loft ; imprefEons ceafed to be
perceived ; vivid ideas pafled rapidly through
the mind, and voluntary power was altogether
deftroyed, fo that the mouth-piece generally
dropt from my unclofed lips.
Whenever the gas was in a high ftate of pu-
rity, it tafted diftindlly fweet to the tongue and
palate, and had an agreeable odor. I often
thought that it produced a feeling fomewhat
analogous to tafte, in its application to my lungs.
In one or two experiments, I perceived a diftincft
fenfe of warmth in my cheft.
I never felt from it any thing like oppreffive
(461 )
refpiration : my infpirations became deep ia
proportion as I breathed it longer ; but this
phaenomenon arofe from increafed energy of the
mufcles of refpiration, and from a defire of in-
creafing the pleafurable feelings.
Generally when I breathed from fix to feven
quarts, mufcular motions were produced to a
certain extent ; fometimes I manifefted my
pleallire by ftamping or laughing only ; at other
times, by dancing round the room and vocife-
rating.
After the refpiration of fmall dofes, the
exhilaration generally lafted for five or fix
minutes only. In one or two experiments
when ten quarts had been breathed for near four
minutes, an exhilai*ation and a fenfe of flight
intoxication lafted for two or three hours.
On May 3d. To afcertain whether the gas
would accelerate or retard the progrefs of fleep,
1 breathed at about 8 o'clock in the evening,
25 quarts of nitrous oxide, in quantities of fix
at a time, allowing but fhort intervals between
each dofe. The feelings were much lefs pleafq-
( 4(52 )
rable than ufual, and during the conluiBption
of the two laft dofes, ahnoft indifferent ; indeed
the gas was breathed rather too foon after its
production and contained fome fufpended acid
vapour which ftimulated the lungs fo as to induce
coughing.
After the experiments, for the firft time I was
fomewhat depreffed and debilitated ; my pro-
penfity to lleep however, came on at the ufual
hour, and as ufual was indulged in, my repofe
was found and unbroken.
Between May and July, I habitually breathed
the gas, occafionally three or four times a day
for a week together ; at other periods, four or
tive times a week only.
The dofes were generally from fix to nine
quarts ; their effeds appeared undiminifhed by
habit, and were hardly ever exadly fimilar.
Sometimes I had the feelings of intenfe intoxi-
cation, attended with but little pleafure ; at
other times, fublime emotions connedled with
highly vivid ideas ; my pulfe was generally in-
«reafed in fulnefs, but rarely in velocity.
( 463 )
The genera! efFefls of its operation upon my
"health and ftate of mind^ are extremely difficult
of defcription ; nor can I well difcriminate be-
tween its agency and that of other phyfical and
moral caufes.
I flept much lefs than ufual, and previous to
fleep, my mind was long occupied by vifible.
imagery. I had a conftant defire of a6lion, a
reftleflhefs, and an uneafy feeling about the
praecordia analogous to the ficknefs of hope.
But perhaps thefe phaenomena in fome mea-
fure depended on the intereft and labour con-
ne(i3ed with the experimental inveftigation re-
lating to the production of nitrous oxide, by
which I was at this time inceffantly occupied.
My appetite was as ufual, and my pulfe not
materially altered. Sometimes for an hour after
the infpiration of the gas, I experienced a fpe-
cies of mental indolence* plcafing rather than
* Mild phyfical pleafure is perhaps always deftrudive to
aftion. Almoft all our powerful voluntary a6lions, arisfe
cither from hope, fear, or deli re ; and the moft powerful
from defire, which is an emotion produced by the coalcf-
cence of hope or ideal pleafure with phyiical pain.
( 464 )
otlierwife, and never ending in riftlefnefs.
During the laft week in which I breathed it
uniformly, I imagined that I had increafed fen-
fibility of touch : my fingers were pained by
any thing rough, and the tooth edge produced
from ilighter caufes than ufual. I was certainly
more irritable, and felt more acutely from
trifling circumftances. My bodily ftrength
was rather diminifhed than increafed.
At the latter end of July, I left off my ha-
bitual courfe of refpiration ; but I continued
occaflonally to breathe the gas, either for the
fake of enjoyment, or with a view of afcertain-
ing its operation under particular circumftances.
In one inflance, when I had head-ache from
indigeftion, it was immediately removed by the
efFefls ofa large dofe of gas; though it after-
wards returned, but with much lefs violence. In
a fecond inftance, a flighter degree of head-ache
was wholly removed by two dofes of gas..
The power of the immediate operation of
the gas in removing intcnfe phyfical pain, I
had a very good opportunity of afccrtaining,
>'' .^
( 433 )
number of experiments, that I took into my
lungs at every natural infpiration, about 13 cu-
bic inches of air, and that I threw out of my
lungs at every expiration,* rather lefs than this
quantity; about 12| cubic inches.
The mean compolition of the 13 cubic inches
of air infpired, was
cub. in.
Nitrogene . . 9,5 ^
Oxygene . , . 3,4
Carbonic acid 0,1
That of the 12,7 of air expired
Nitrogene . . 9,3
Oxygene . . 2,2
Carbonic acid 1,2
Thefe refults I gained from more than 20 ex*
periments, fo that I could not poffibly entertain
any doubt of this accuracy.
I found, by making a perfon obferve my ref-
pirations when I vvas inattentive to the procefs.
* The diminution of air by iingle infpirations, waj
particularly noticed by Dr, Goodwyn.
( 434 )
that I made about 26 or 27 natural infpirations
in a minute; So that calculating' from the
above eftimations^ it would follow, that 31.6
cubic inches of oxygene were confumed, and
5,2 inches of nitrogene loft in refpiration every
minute, whilft 26,6 cubic inches of carbonic
acid were produced.
To collefl the produd^s of a great number of
natural expirations fo as to afcerlain whether
their compofttion correfponded with the above
accounts, I proceeded in the following manner.
I faftened my lips tight on the mouth-piece
of the exhaufted airholder, and fufFering my
noftrils to remain open, infpired naturally
through them, throwing the expired air through
my mouth into the airholder.
In many experiments, I found that in about
a half a minute, I made in this way 14 or 15
expirations. The mean quantity of air colleded'
was 171 cubic inches, and confiftcd of
cub. in.
Nitrogene .. 128
Oxygene . . 29
Carbonic acid . . 14
( 435 )
Comparing tliefe rcfults with the former ones^
we find the mean quantities of air refpired in
equal terms rallier Icfs ; but the proportions , of
carbonic acid, nitrogcne and oxygene in the
refpired air, nearly identical.
e. To afcertaln the changes effected in a
given quantity ot atmofpheric air by continued
refpirations, I breathed after a compleat expi-
ration, at ten)perature 63O5 161 cubic inches of
air for near a minute, making in this time, 19
deep infpirations. After the compleat expira-
tion, which was very carefully made, the gas
filled a fpace nearly equal to 152 cubic inches^
fo that 9 cubic inches of gas had difappeared.
The 152 cubic inches analifed, were found
to confifl: of
cub. in.
Nitrogene . . 111,6
Oxygene . . 23,
Carbonic acid, 17,4
The 161 cubic inches before infpirationy were
compofed of
( 436 )
cub. In.
Nitrogene . . 1 1 7.0
Oxygen e . . 4*2,4
Carbonic acid ]56
Bat the refidual gas in the lungs before the
experiment, was of different compofition from
that remaining in the lungs after the expe-
riment. Making corredlions on account of
this circumftance, as in fe6lion IV. it appears
that about 5,1 of nitrogene were abforbed in
refpiration, 23,9 of oxygene confumed, and
12 of carbonic acid produced.
I repeated this experiment three times ; in
each experiment the diminution after refpiration,
was nearly the fame ; and the refidual gas
making the neceflary allowances, of fimilar
compofition. So that fuppofing the exiftencc
of no fource of error in the experiments from
which the quantity and compofition of the red-
dual gas of the lungs were eftimated in fedlion
IV. the abforption of nitrogene by the venous
blood, appears almoft demon ftrated.
{ 437 )
/. To compare the changes efFedled in at-
mofpheric air by refpiration of the fmaller
quadrupeds, with thofe in the experiments juft
detailed, I introduced into a jar of the capacity
of 20 cubic inches filled with mercury in the
mercurial trough, 15 cubic inches of atmofphe-
ric air which had been deprived of its carbonic
acid by long expofure, to folution of potafh.
Temperature being 64^, a healthy fmall
moufe was quickly p^^iled under the mercury
into the jar, and fufFered to reft on a very thin
bitofcheefe, which was admitted immediately,
after.
He continued for near 40 minutes without
apparently fufF^ring, occafionallj railing him-
felf on his hind legs. At the end of 50 minutes,
he was lying on his fulc, and in 55 minutes
was apparently dying. He was now carefully
taken out through the mercury by the tail, and
expofed before the fire, vvhere he foon recovered.
After the cheefe had been carefully removed,
the gas in the jar filled a fpace nearly equal to
14 cubic inches; fo that a diminution of a
( 438 )
cubic inch had taken place. Thefe 14 cub:C
inches analifed^ were found to confift of
cub. in.
Carbonic acid . , 2.0
Oxygene .... 1,4
Nitrogene . . . 10,6
The 15 cubic inches before the experimentj
confifted of
cub. in.
Oxygene . . 4
Nitrogene . . 11
•Hence it appeared, that 2,6 cubic inches of
oxygene had been confumed, 2 cubic inches
of carbonic acid produced, and about 0,4 of
nitrogend"loft.
The relation between the quantities of oxy-
gene confumed in this experiment, and the
carbonic acid produced, are nearly the fame as
that of thofe in the experiments jufl detailed ;
but the quantity of nitrogene loft is much
fmaller.
( 439 )
VII. Refpiration of Oxygene,
The gafes before and after refpiration, were
analifed in thefe experiments in the manner
defcribed in the laft fedlion, except that 3 of
nitrous gas were always employed to one of
oxygene.
E. I. At temperature 53°, after a full forced
refpiration, I refpired in the mercurial airholder,
for half a minute^ 102 cubic inches of oxygene,
making feven very long and deep infpirations.
After the compleat expiration, the gafes filled
a fpace equal to QS cubic inches ; thefe 93
cubic inches analiled, were found to confifl; of
cub. in.
Carbonic acid . . 5,9
Nitrogene .... 33,8
Oxygene 53,3
The 102 cubic inches before the experiment,
were compofed of
cub. in.
Oxygene . , 78
Nitrogene . , 24
( 440 )
The refidual gas in the lungs before the expe-
riment, was 32 cubic inches, and compofed of
about 23 nitrogene, 4,1 carbonic acid, and 4,9
oxygene, Sedlion IV. The refidual gas after
expiration, was compofed of 18,2 oxygene,
2 carbonic acid, and 11,8 nitrogene.
Hence the whole of the gas in the lungs and
airholder before infpiration, was 134 cubic
inches, compofed of
cub. in.
Oxygene . . 82,9
Nitrogene . . 47,0
Carbonic acid . . 4,1
And after refpiration, 125 cubic inches, con-
fifting of
cub. in.
Oxygene .... 71,5
Nitrogene .... 45,6
Carbonic acid . . 7,9
So that comparing the quantities, it appears,
that 11,4 of oxygene and 1,4 of nitrogene,
were confumed in this experiment, and 3,8 of
carbonic acid produced.
( 441 )
I was much furprlfed at the ftnall quantity of
oxygene that had been confumed in this expe-
riment. This quantity was lefs than that ex-
pended during the refpiration of atmofpheric
air for half a minute : the portion of carbonic
acid evolved was likewife fmaller. I could
dete(^ no fource of inaccuracy, and it was diffi-
cult to fuppofe that the greater depth and
fulnefs of the infpirations could make any
difference.
E. 2, I now refpired at the fame tempera-
ture, after a full expiration, 162 cubic inches
of gas, compofed of 133 oxygene and 29 nitro*
gene for two minutes, imitating as much as
poffible, the natural refpiration. After the oc-
periment, they filled a fpacc equal to 123 cubic
inches. And when the analyfis and calcula-
tions had been made as in the lad experiment,
it appeared that 57 cubic inches of oxygene,
and 2 of nitrogene had been abfbrbed, whilft
21 cubic inches of carbonic acid had been
formed.
Now from the eftimations in the laft fc(51ipn.
( 442 )
it appears that 63 cubic inches of oxygene are
confumed, and about 52 cubic inches of car-
bonicacid produced every two minutes during the
natural refpiration of cominon air. So that
fuppofing the experiment accurate, 6 cubic
inches of oxygene lefs are abforbed, and 30
cubic inches lefs of carbonic acid produced
every minute, when oxygene nearly pure is
refpired, than when atmofpheric air is refpired.
Both thefe experiments were made in the
nnorning, at a time when I was in perfedl health ;
fo that there could be apparently no fource of
error from accidental circumftances.
The uncommon and unexpedied nature of the
refults, made me however, very fceptical con-
cerning them ; and before I would draw any
inferences, I refolvcd to afcertain the compara-
tive confumption of atmofpheric air and oxy-
gene by the fmaller quadrupeds, for which pur-
pofe, I made the following experiment.
E. 3. Of two ftrong and healthy fmall mice,
apparently of the fame breed, and cxadly
fimilar.
{ 443 )
One was introduced. into ajar containing 10
cubic inches and ba4f of oxygene, and 3 cubic
inches of nitrogcne^ and made to reft on a bit
of cheefe.
The other was introduced into a jar contain-
ing fifteen cubic inches and half of atmofpheric
air, and made to reft in- the fame manner on
cheefe.
The moufe in oxygene began apparently to
fuffer in about half an hour, and occafionally
panted very much; in about an hour he lay
down on his fide as if dying. The jars were
often agitated, that the gafes might be well
mingled.
The moufe in atmofpheric air became very
feeble in 40 minutes, and at the end of 50 mi-
nutes was taken out through the mercury alive,
but unable to ftand.
The moufe in oxygene was taken out in the
fame manner after an hour and quarter, alive,
but motionlefs, and breathing very deeply.
The gas in the jars Vv'as examined. That in
the oxygene jar filled a fpace exadlly equal to
f 444 )
12,7 cubic inches, and analifecl, was found to
confiftof 1,7 carbonic acid, '1,6 of nitrogene,
and 8,4 of oxygene. So that abfohitely, 2,1
cubic inches of oxygene and ,4 ofnitrogenehad
been con fumed, and 1,7 of carbonic acid pro-
duced.
The gas in the atmofpheric air jar was dimi-
nifhed nearly to 14,4, and confilted of 2,1 car-
bonic acid, 1,4 oxygene; and 10,9 nitrogene.
So that 2,7 of oxygene and ,5 of nitrogene, had
been confumed by the moufe ; and 2,1 of car-
bonic acid produced.
Hence it appear^, that the moufe in atmof-
pheric air confumed nearly one-third more oxy-
gene and produced nearly one-fourth more
carbonic acid in refpiration in 55 minutes, than
the other in an hour and quarter in oxygene.
And if we confider the perpetual diminution of
the oxygene of the atmofpheric air ; from which
at laft it became almoll incapable of fupporting
the life of the animal ; we may conclude, that
the quantity of oxygene confumed by it, had
( 445 )
the air been perpetually renovated, would have
been much more confiderable.
I delign very fnortly, to repeat thefe experi-
ments, and to make others on the comparative
confumption of oxygene and atmofpheric air,
by the larger quadrupeds. Whatever may be
the refults, I hope to be able to alcertain from
them, why pure oxygene is incapable of fup-
porting life.
VIII. Objervations on the changes effeBed
m the Mood, by atmofpheric air and oxygene.
From the experiments of Mr. Cigna and Dr.
Prieftley,* it appears that the coagulum of the
venous blood becomes florid at its furface when
expofed to the atmofphere, though covered and
defended from the immediate contadt of air by
averv thick ftratum of ferum.
* Dr. Priellley found that it likewife became florid at
the furface when covered by milk ; but that it underwent
little or no alteration of color under water and motl other
fluids.— Vol. 3. p. 373
( 446 )
Hence it is evident, that lerum is capable of
difrolving either the whole compound atmofphe-
ric air, or the oxygen e of it.
Suppofing what indeed is moll: probable from
numerous analogies, that it diflblves the whole
compound ; it would follow, that the coloring
of thecoagulum of blood under ferum, depended
upon the decompofition of the atmofpheric air
condenfed in the ferum, the oxygene'|~ of it
combining with the red particles, and the nitro-
gene cither remaining diflblved in the fluid, or
being liberated through it into the atmofphere.
Now the circulating blood conlifts of red par-
ticles, floating in and ditFufed through ferum
and coagulablc lymph.
f There are many analogous decorapofitions. Dr. Prieftley
noticed (and I have often made the obfervalion) that green
oxide of iron, or the precipitate from pale green fulphatc
of iron by cauftic alkali, becanie red at the furface, when
covered by a thick ftratum of water. In my experiments on
the green muriate and lulphate of iron, I obfervcd that part
of fome dark oxide , of iron which was at the bottom of a
trough of water Q inches deep, became red at the furface
nearly in the fame time as another portion of the fame preci-
pitation that was expofed to the atmofphere. This oxyge-
nation muft depend upon the decompofition of atmofpheric
air conftantly diflblved by the water.
( 447 )
In natural refpiration^ the red particles are ren^
dared of a brighter tinge during the paffage of
the blood through the pulmonary veins. And
as we have feen in the lait feclions, during ref-
pi ration atmofpheric air is decompofed \ all the
oxygene of it confumed^ apparently a fmall
portion of the nitrogene loft, and a confiderable
quantity of carbonic acid produced.
It feems therefore reafonable to fuppofe, that
the whole compound atmofpheric air paffing
through the moill coats of the veflTels is firft
diflblved by the ferum ofthe venous blood, and in
its condenled ftate, decompofed by the affinity
of the red particles for its oxygene ; the greater
part of the nitrogene being liberated unaltered ;
but a minute portion of it poffibly remaining
condcnfcd in the ferum and coagulable lymph,
and palling with them into the left chamber of
the heart.
From the experiments on the refpiration of
nitrous oxide and hydrogene, it appears that a
certain portion of the carbonic acid produced in
refpiration, is evolved from the venous blood \
( 448 )
but as a much greater quantity is generated
during the refpiration of common air and oxy-
gene, than during that of hydrogene in equal
times, it is not impoffible but that Tome portion of
it may be formed by the combination of charcoal
in the red particles with the oxygene diilblved
in the ferum ; but this can only be determined
by farther experiments.
Suppofing that no part of the water evolved
in folution by the expired gas of common air is
formed immediately in refpiration, it will follow
that a very confiderable quantity of oxygene
muft be confiantly combined with the red par-
ticles, even allowing the confumption of a
certain portion of it to form carbonic acid ; for
the carbonic acid evolved, rarely amounts to
more than three-fourths of the volume of the
oxygene confumed.
Perhaps the ferum of the blood is capable of
difTolving a larger quantity of atmofpheric air
than of pure oxygene. On this fuppofition, it
would be eafy to explain the fmallcr confumption
of oxygene in the experiments in the laft fediion^
{ 465 )
in cutting one of the unlucky teeth called
dentes fapientiae, I experienced an extenfive
inflammation of the gum, accompanied with
great pain, which equally deUroyed the power
of repofe, and of confiftent action.
On the day when the inflammation was moit
troublefome, I breathed three large dofes of
nitrous oxide. The pain always diminiflied
after the firft four or five infpirations ; the thril-
ling came on as ufual, and uneafinefs was for a
few minutes, fwallowed up in pleafure. As the
former flate of mind however returned, the
itate of organ returned with it; and I once
imagined that the pain was more fevere after
the experiment than before.
In Augaft, I made many experiments with a
view of afcertaining whether any analogy exilted
between the fenfible effects of the different ga-
{es which are fooner or later fatal to life when
refpired, and thofe of nitrous oxide.
I refpired four quarts of Hydrogene* nearly
♦ Pare hydrogene has been often refpired by diflferent
Philofophers, partictalarly by Schecle, Fontana, and the
adyentaroQS and anfortunate Rofier.
( 466 )
pore produced from zinc and muriatic acid^ for
near a minute, my lungs being previoufly ex-
haufted and my noftrils carefully clofcd. The
firft fix or feven infpirations produced no fenfa-
tions whatever ; in half a minute, I perceived
a difagreeable oppreffion of the cheft, which
obliged mc to refpire very quickly ; this op-
preffion gradually increafed, till at laft the pain
of fufFocation compelled me to leave off breath-
ing. I felt no giddinefs during or after the
experiment ; my pulfe was rendered feebler and
quicker ; and a by-ftander informed me that
towards the laft, my cheeks became purple.
In a fecond experiment, when the hydro-
gene was procured from iron and diluted ful-
phuric acid, I was unable to refpire it for fo
long as three quarters of a minute ; a tranfient
giddinefs and mufcular debility were produced,
the pulfe was rendered very feeble, and the pain
of fufFocation was greater than before.
I breathed three quarts of Nitrogene mingled
with a very fmall portion of carbonic acid, for
near a minute. It produced no alteration in
{ 467 )
tny fenfatlons for the firft twenty feconds ; then
the painful fenfe of fnfFocation gradually came
on, and increafed rapidly in the laft quarter of
the minute,' fo as to oblige me to defifl: from
the experiment. My pulfe was rendered feebler
and quicker. I felt no afFe6lion whatever in
the head.
Mr. Watt's obfervations on the refpiration
of diluted Hydrocarbonate by men, and Dr.
Beddoes's experiments on the deftrudlion of
animals by pure hydrocarbonate, proved that
its efFe6ls were highly deleterious.
As it deftroyed life apparently by rendering
the mufcular fibre inirritable without producing
any previous excitement, I was anxious to com-
pare its fenfible efFeds with thofe of nitrous
oxide, which at this tiuie I believed to deftroy
life by producing the higheft poffible excite-
ment, ending in laefion of organifation.
In the firft experiment, I breathed for near
a minute, three quarts of hydrocarbonate min-
gled with nearly two quartsof atmofpheric air.*
* I believe it had never been breathed before by any
individual, in a ftate fo little diluted.
( 468 )
It produced a flight giddinefs and pain in the
head, and a momentary lofs of voluntary power :
my pulfe was rendered much quicker and feeb-
ler. Thefe efFe6ls however, went off in five
minutes, and I had no return of giddinefs.
Emboldened by this trial, in which the feel-
ings were not unlike thofe I experienced in the
firft experiments on nitrous oxide, I refolved
to breathe pure bydrocarbonate.
For this purpofe, I introduced into a filk bag,
four quarts of gas nearly pure, which was care-
fully produced from the decompolition of water
by charcoal an hour before, and which had a
vary flrong and difagreeable fmell.
My friend, Mr. James Tobin, Junr. being
prefent, after a forced exhauftion of my lungs,
the nofe being accurately clofcd, I made three
infpirations and expirations of the bydrocarbo-
nate. The firft infpiration produced a fort of
numbnefs and lofs of feeling in the cheft and
about the pedloral mufcles. After the fecond
infpiration, I loft all power of perceiving exter-
nal things, and had no diftind fenfation except
( 469 )
a terrible oppreffion on the cheft. During the
third expiration^ this feeling difappeared, I
leemed finking into annihilation, and had juft
power enough to drop the mouth-piece from my
unclofed lips. A fhort interval muft have paf-
fed during which I refpired common air, before
the objedls about me were diftinguifhable. On
recolledling myfelf, I faintly articulated, " / do
not think I Jhall ciie,^'' Putting my finger on
the wrift, I found my pulfe thread-like and
beating with excefiive quicknefs.
In lefs than a minute, I was able to walk, and
the painful oppreflion on the chefl diredted me
to the open air.
After making a few fl:eps which carried me to
the garden, my head became giddy, my knees
trembled, and I had jufi: fufficient voluntary
power to throw myfelf on the grafs. Here the
painful feeling of the cheft increafed with fuch
violence as to threaten fufix)cation. At this
moment, I aiked for fome nitrous oxide. Mr.
Dwyer brought me a mixture of oxygenc and
nitrous oxide. I breathed this for a minute, and
( 470 )
helieved royfelf relieved. In five minutes, the
painful feelingvS began gradually to diminilli.
In an hour they had nearly difappeared, and I
felt only exceflive wcaknefs and a flight fwim-
ining of the head. My voice was very feeble
and indiftin^l. This was at tvi'o o'clock in the
afternoon.
I afterwards walked flowly for about half an
hour, with Mr. Tobin, Junr. and on my return,
was fo much fironger and better, as to believe
that the effects of the gas had difappeared ;
though my pulfe was 120 and very feeble. I
continued without pain for near three quarters
of an hour; when the giddinefs returned with
fuch violence as to oblige me to lie on the bed ;
it was accompanied with naufea, lofs of me-
mory, and deficient fenfation. In about an
hour and half, the giddinefs went off, and was
fucceeded by an excruciating pain in the fore-
head and between the eyes, with trantient
pains in the chcfl and extremities.
Towards night thefe afFediions gradually dimi-
( 171 )
nifhed. At ten,t no difagreeable feeling ex-
cept weaknefs remained. I flept founds and
awoke in the morning very feeble and very
hungry. No recurrence of the fymptoms took
place, and I had nearly recovered rny ftrength
by the evening.
I have been minute in the account of this
experiment becaufe it proves, that hydrocarbo-
nate sl6\s as a fedative, i. e. that it produces
diminution of vital action, and debility, v^ithout
previoufly exciting. There is every reafon to
believe, that if I had taken four or five infpira-
tions inftead of three, they would have deftroyed
life immediately without producing any painful
fenfation. Perhaps moft of the uneafy feelings
after the experiment, were connecl^ed with the
return of the healthy condition of organs.*
j I ought to obfervc, that between eight and ten, I took
by the advice of Dr. Beddoes, two or three dofes of diluted
nitric acid.
* By whatever caufe the exhauftion of organs is produ*
ced, pain is almoft uniformly conne6ted with their return-
ing health. Pain is rarely ever perceived in limbs debilitated
( m)
About a week after this experiment, I at-
tempted to refpire Carbonic acid, not being at
the tim'e acquainted with the experiments of
Rofier.
I introduced into a filk bag four quarts of
well wafhed carbonic acid produced from carr
bonate of ammoniac* by heat, and after a
compleat voluntary exhauftion of my lungs,
attempted to infpire it. It tafted llrongly acid
in the mouth and fauces, and produced a fenfe
of burning at the top of the uvula. In vain I
made powerful voluntary efforts to draw it into
the windpipe ; at the moment that the epiglottis
was raifed a little, a painful Simulation was in-
duced, fo as to clofe it fpafmodically on the
glottis ; and thus in repeated trials I was pre-
vented from taking a tingle particle of carbonic
acid into my lungs.
by fatigue till after they have been for fome hours at reft.
Pain is uniformly conne6ted with the recovery from the
debility induced by typhus, often with the recovery from
that produced by the ftimulation of opium and alcohol.
* Carbonic acid is produced in this way in a high ftata
of purity," and with great readinefs.
( 473 )
I tried to breathe a mixture of two quarts of
common air and three of carbonic acid, without
fuccefs ; it Simulated the. epiglottis nearly in
the fame manner as pure carbonic acid, and
was perfedlly non-refpirable.
I found that a mixture of three quarts of car-
bonic acid with feven of common air was refpi*
rable, I breathed it for near a minute. At the
time, it produced a flight degree of giddinefs,
and an inclination to lleep. Thefe effedls how-
ever, very rapidly difappeared after I had ceafed
to breathe, =* and no other afFedlions followed.
During the courfe of experiments on nitrous
oxide, I feveral times breathed Oxygene procu-
red from manganefe by heat, for from three to
five minutes.
In refpiring eight or ten quarts ; for the firft
* Carbonic acid pofTeffes no adion on arterial blood.
Hence perhaps, its flight efFeds when breathed mingled
with large quantities of common air. Its efFeds are very-
marked upon venous blood ! If it were thrown forcibly
into the lungs of animals, the momentary application of it
to the pi^lraonary venous blood would probably defbroy life.
( 474 )
two or three minutes I could perceive no effecls.
Towards the end, even when I breathed very
flowly, my refpiration became oppreiTed, and
I felt a fenfation analogous to that produced by
the want of frefh air; though but little of the
oxygene had been con fumed.
In one experiment when I breathed from and
into a bag containing 20 quarts of oxygene for
near fix minutes ; Dr. Kinglake felt my pulfe,
and found it not altered in velocity, but rather
harder than before. I perceived no effeds but
thofe of oppreffion on the cheft'^.
^ In a converfation with Mr. Watt, relating to the pow-
ers of gafes, that excellent philofophcr told me he had for
fome time entertained a fufpicion, that the effects attribu-
ted to oxygene produced from manganefe by heat, in fome
meafure depended upon nitrous acid fufpended in the gas,
formed during ignition by the union of fome of the oxygens
of the manganefe with nitrogene likewife condenfed in it.
In the courfe of experiments on nitrous acid, detailed in
Refearch I. made in September, 06tober, and December,
1799, I feveral times experienced a fevere oppreflion on the
cheft and difficulty of refpiration, not unanalogous to that
produced by oxygene, but much more violent, from
breathing an atmofphere loaded with nitrous acid vapour.
This fa6t feemcd to confirm Mr. Watt's fufpicion. I con-
( 475 )
Having obferved in my experiments upon
venous blood, that Nitrous gas rendered that
fluid of a purple tinge, very like the color
generated in it by nitrous oxide ; and finding
no painful efFe6ls produced by the application
of nitrous gas to the bare rnufcular fibre, I
began to imagine that this gas might be breathed
with impunity, provided it were poffible in any
way to free the lungs of common air before in-
fpiration, fo as to prevent the formation of
nitrous acid.
On this fuppofition, during a fit of enthufi-
afm produced by the refpiration of nitrous
oxide, I refolved to endeavour to breathe
Nitrous gas.
114 cubic inches of nitrous gas were intro-
duced into the large mercurial airholder ; two
fefs, however, that I have never been able to dete6l any
fnnell of nitrous acid, either by means of my own or-
gans or thofe of others, during the prodadion of oxygene :
when the gas is fuffered to pafs into the ntmofpherc.
The oxygene breathed in the experiments detailed in the
text, had been for fome days in conta^^ with water.
(476)
fmall filk bags of the capacity of feven quarts
were filled with nitrous oxide.
After a forced exhauftion of my lungs, my
nofe being accurately clofed, I made three in-
fpirations and expirations of nitrous oxide in
one of the bags, to free my lungs as much as
poffible from atmofpheric oxygene ; then, after
a full expiration of the nitrous oxide, I transferred
my mouth from the mouth -piece of the bag to
that of the airholder, and turning the ftop-
cock, attempted to infpire the nitrous gas. —
In paffing through my mouth and fauces, it
tafted aflringent and highly difagreeable ; it
occafioned a fenfe of burning in the throat, and
produced a fpafm of the epiglottis fo painful as
to oblige me to defift inflantly from attempts
to infpire it. After moving my lips from the
mouth-piece, when I opened them to infpire
common air, aeriform nitrous acid was inflantly
formad in my mouth, which burnt the tongue
and palate, injured the teeth, and produced an
inflammation of the mucous membrane which
lafted for fome hours.
( 4/7 )
As after the refpiration of nitrous oxide in
the experiments in the laft Refearch, a fmall
portion of the refidual atmofpheric air rejnained
in the lungs, mingled with the gas, after forced
expiration ; it is mod probable that a minute
portion of nitrous acid was formed in this expe-
riment, when the nitrous gas was taken into
the mouth and fauces/ which might produce
its {Simulating properties. If fo, perhaps I
owe my life to the circumflance ; for fup-
pofing I had taken an infpiration of nitrous
gas, and even that it had produced no
pofitive cfFedls, it is highly improbable, that
by breathing nitrous oxide, I fhould have freed
my lungs from it, fo as to have prevented the
formation of nitrous acid when I again infpired
common air. I never defign again to attempt
fo rath an experiment.
In the beginning of September I often ref-
pired nitrous oxide mingled with different pro-
portions of common air or oxygene. The
efFedls produced by the diluted gas were much
lefs violent than thofe produced by pure nitrous
( 47S )
/
oxide. They were generally pleafant : the
thrilling was not often perceived, but a fenfe
of exhiHration was almoft conftant.
Between September and the end of Odlober,
I made but few experiments on refpiration, al-
moft the whole of my time being devoted to
chemical experiments on the produdion and
analylis of nitrous oxide.
At this period my health being fomewhat
injured by the conftant labour of experiment-
ing, and the perpetual inhalation of the acid
vapours of the laboratory, I went into Cornwal ;
where new aflbciations of ideas and feelings,
common exercife, a pure atmofphere, luxurious
diet and moderate indulgence in wine, in a
month reftored me to health and vigor.
Nov. 27th. Immediately after my return,
being fatigued by a long journey, I refpired
nine quarts of nitrous oxide, having been pre-
cifely thirty-three days without breathing any.
The feelings were different from thofe I had
experienced in former experiments. After the
firft fix or feven infpirations, I gradually began
( 479 )
to lofe the perception of extei^al things^ and a
vivid and intenle recolIe6lion of fome former
experiments paffed through my mind, fo that
I called out *^ "what an amazing concatenation of
ideas P' I had no pleafurable feeling whatever,
I ufed no mufcular motion, nor did I feel any
difpofition to it ; after a minute, when I made
the note of the experiment, all the uncommon
fenfations had vanifhed ; they were fucceeded
by a flight forenefs in one of the arms and in
the leg : in three minutes thefe affections like-
wife difappeared.
From this experiment I was inclined to uip-
|jofe that my newly acquired health had dimi-
nifhed my fufceptibility to the effefls of the
gas. About ten days after, however, I had an
opportunity of proving the fallacy of this fupL-
pofition.
Immediately after a journey of \*lQ miles, in
which I had no fleep the preceding night, being
much exhaufed, I fefpired feven quarts of gas
for near three minutes. It produced the ufual
pleafurable effefls, and flight mufcular motion.
( 480 )
I continued exhilarated for fome minutes after-
wards: but in half an hour found myfelf neither
more or lefs exhaufted than before the experi-
ment. I had a great propenfity to fleep.
I repeated the experiment four or five times
in the following week, with fimilar eftedls. M}^
fufceptibility was certainly not diminifhed. I
even thought that I was more affedled than for-
merly by equal dofes.
Though, except in one inflance, when indeed
the gas was impure, I had experienced no decifive
exhauftion after the excitement from nitrous ox-
ide, yet ftill I was far from being fatisfied that it
was unanalogous to ftimulants in general. —
No experiment had been made in which the
excitement from nitrous oxide had been kept up
for fo great a length of time and carried to fo
great an extent as that in which it is uniformly
fucceeded by exceffive debility under the agency
of other powers.
It occurred to me, that fuppofing nitrous ox-
ide to be a ftimulant of the common clafs, it
would follow that the debility produced in con-
( 481 )
fequence of excefRve ftiniulation by a known
agent, ought to be increafed after excitement
from nitrons oxide.*
To afcertain whether this was the cafe, I
made on December 23d, at four P. M. the
following experiment. I drank a bottle of
wine in large draughts in lefs than eight mi-
nutes. Whilfl I w.as drinking, I perceived a
fenfe of fulnefs in the head, and throbbing of
the arteries, not unanalogous to that produced ia
the firft ftage of nitrous oxide excitement.
After I had finifhed the bottle, this fulnefs in-
creafed, the obje6ls around me became dazzling,
the power of diftindl articulation was loft, and
I was unable to walk fteadily. At this moment
the fenfations were rather pleafurable than other-
wife, the fenfe o^ fulnefs in the head foon how-
ever increafed lb as to become painful,- and in
* In the fame manner as the debility from intoxicatioB
b/ two bottles of wine is increafed by a third.
Gg
( 462 )
left than an hour I funk into a ftate of infenfi-
bility.*
In this fituation 1 muft have remained for
two hours or two hours and half.
I was awakened by head-ache and painful
naufea. The naufea continued even after the
contents of the flomach had been ejefled. The
pain in the iiead every minute increafed ; I was
neither feverifh or thirfty ; my bodily and men-
tal debility were exceffive, and the pulfe feeble
and quick. .
In this ftate I breathed for near a minute and
half five quarts of gas, which was brought to
me by the operator for nitrous oxide ; but as it
produced no fenfations whatever, and apparently
rather increafed my debilty, I am almoft con-
vinced that it was from fome accident, either
common air, or very impure^nitrous oxide.
Immediately after this trial, I refpired 12 quarts
* 1 ought to obferve that my ufual drink is water, that
I had been little accuftomcd to take wine or fpirits, and
had never been compleatly intoxicated but once before in
the courfe of my life. This will account for the powerful
eifc^ of a Single bottle of win*.
{ MB )
ofoxygexit for near four minutes. It produced
no alteration in my fenfations at the time ; but
immediately after I imagined that I was a little
exhilirated.
The head- ache and debility ftill however
continuing with violence, I examined fome
nitrous oxide which had been prepared in the
morning, and finding it very pure, refpired
feven quarts of it for two minutes and half.
I was unconfcious of head-ache after the third
infpiration 5 the ufual pleafurable thrilling was
produced, voluntary power was defiroyed, and
vivid ideas rapidly pafTed through my mind ; I
made ftrides acrofs the room, and con-
tinued for fome minutes much exhilirated.
Immediately after the exhilaration had difap-
peared^ I felt a flight return of the head-ache ;
it was connefled with tranfient naufea. After
two minutes, when a fmall quantity of acidified
wiae had been thrown from the flomach, both the
naufea and head-ache difappeared ; but languor
and depreffion not very different in degree from
thofc exifting before the experiment, fucceeded.
( 484 )
They however, gradually went off before bed
time. I flept found the whole of the night
except for a few minutes, during which I was
kept awake by a trifling head-ache. In the
morning, I had no longer any debility. No
head-ache or giddinefs came en after I had
arifen, and my appetite was very gi'eat.
This experiment proved, that debility from
intoxicf^tion was not increafed by excitement
from nitrous oxide. The headache and de-
preffion, it is probable, would have continued
longer if it had not been adminiftered. Is it
not likely that the flight naufea following
the efFedts of the gas was produced by new
excitability given to the ftomach ?
To afcertain ivith certainty, whether the
moft extenfive adlion of nitrous oxide compa-
tible with life, was capable of producing debility,
I refolved to breathe the gas for fuch a time and
in fuch quantities, as to produce excitement
equal in duration and fuperior in intenfity to
that occafioned by high intoxication from opium
or alcohol.
( 485 )
To habituate myfelf to the excitement, and
to carry it on gradually
On December 26th, I was inclofed in an
air-tight breathing-box,* of the capacity of
about 9 cubic feet and half, in the prefence of
Dr. Kinglake.
After I had taken a fituation in which I could
by means of a curved thermometer inferted
under Ihe arm, and a (lop-watch, afcertain the
alterations in my pulfe and animal heat, 20
quarts of nitrous oxide were thrown into the
box.
For three minutes I experienced no altera-
tion in my fenfations, though immediately after
the introdu^lion of the nitrous oxide the fmell
and tade of it were very evidcutJ
In four minutes I began to feel a flight glow
'^ The plan of this box was communicated by Mr. Watt.
An account of it will be detailed in the Befearches.
\ The nitrous oxide was too diluted to afl much ; it
was mingled with near i?2 times it* bulk of atmofpht ric
air.
( 486 )
in the cheeks, and a generally difFufed warmth
over the cheft, though the temperature of the
box was not quite 50®. I had negledied to feel
my pulfe before I went in ; at this time it was
104 and hard, the animal heat was 08®. In
ten minutes the animal heat was near gg% in a
quarter of an hour 99.5°, when the pulfe was
102, and fuller than before.
At this period 20 quarts more of nitrous oxide
Mrere thrown into the box, and well-mingled
with the mafs of air by agitation.
In 25 minutes the animal heat was loo»,
pulfe 124. In 30 minutes, !K) quarts more of
gas were introduced.
My fenfations were now pleafant ; I had a
generally difFufed warmth without the flighteft
moifture of the fkin, a fenfe of exhilaration
fimilar to that produced by a fmall dofe of wine,
and a difpofition to mufcular motion and to
merriment.
In three quarters of an hour the pulfe was
104, and animal heat not 99,5"^, the tempera-
ture of the chamber was 64^ The pleafurabl^
r 487 )
feelings continued to increafe, the pulfe became
-fuller and flower, till in about an hour it was
880, when the animal heat was 99°.
20 quarts more of air were admitted. I had
now a great difpoiition to laugh, luminous points
feemed frequently to pafs before my eyes, m}i
hearing was certainly more acute and I felt a
pleafent lightnefs and power of exertion in my
mufcles. In a (hort time the fymptoms became
ilationary ; breathing was rather opprefled, and
on account of the great defire of action, reft
was painful.
I now came out of the box, having been in
precifely an hour and quarter.
The moment after, I began to refpire 20 quarts ^
of unmingled nitrous oxide. A thrilling ex-*
tending from the cheft to the extremities was
almoft immediately produced. I felt a fenfe of
tangible extenfion highly plcafurable in every
limb ; my vifible impreflions were dazzling
and apparently magnified, I heard diflindlly
every found in the room and was perfe(Sly aware
( 488 )
of my fituation.* By degrees as the pleafurable
fcnfations increafed, I loft all conne61ion with
external things; trains of vivid viiible images
rapidly pafled through my mind and were con-
nedled with words in fuch a manner, as to pro-
duce perceptions perfe6lly novel. I exifted in
a world of newly conne^led and newly modified
ideas. 1 theorifed ; I imagined that I made
difcoveries. When I was awakened from this
femi-delirious trance by Dr. Kinglake, who
took the bag from my_ mouthy Indignation
and pride were the firft feelings produced by
the fight of the perfons about me. My emotions
were enthufiaftic and fublime ; and for a minute
I, walked round the room perfedly regardlefs
of what was faid to me. As I recovered my
former ftate of mind, I felt an inclination to
communicate the difcoveries I had made during
the experiment. I endeavoured to recall the
ideas, they were feeble and indiftinfl ; one
collection of terms, however, prefentcd itfelf;
* In all thefe experiments after the liril minute, my
cheeks became purple.
( 489 )
&nd with the mod intenfe belief and prophetic
manner, I exclaimed to Dr. Kinglake, " Nothing
exijis hut thoughts ! — the univerfe is compofed of
imprejjions^ ideas, pJeafures and pains /"
About three minutes and half only, had elap-
fed during this experiment, though the time as
meafured by the relative vividnefs of the recol-
le6led ideas, appeared to me much longer.
Not more than half of the nitrous oxide was
confumed. After a minute, before the thrilling
of the extremities bad difappeared, I breathed
the remainder. Similar fenfations were again
produced ; I was quickly thrown into the plea-
furable trance, and continued in it longer than
before. For many minutes after the experiment,
I experienced the thrilling in the extremities,
the exhilaration continued nearly two hours.
For a much longer time I experienced the mild
enjoyment before defcribed connedled with
indolence ; no depreffion or feeblenefs followed.
I ate my dinner with great appetite and found
myfelf lively and difpofed to a6iion immediately
after. I pafled the evening in executing cxpe-.
( 490)
rimettts. At night I foatid myfelf unofually
cheerful ai>d aflive ; and the hours between
eleven and two, were fpent rn copying the fore-
going detail from the common-place book and
in arranging the experiments. In bed I en-
joyed profound repofe. When I awoke in the
*morning, it was with confcioufnefe of pleafura*
ble exiftence, and this confeioufnefe more or
lefs, continued through the day.
Since December, I have very often brealbed
nitrous oxide. My fufceptibility to its power^
is rather increafed than diminifhed. I find i>x
quarts a full dofe, and I am rarely able to re(^
pire it in.any quantity for more than two minutes
and half.
The mode of its operation is fomewhat alte-
red. It is indeed very different at different
times.
I am fcarcely ever excited into violent muf-
cular aftion, the emotions are generally much
Icfs intenfe and fublime than in the former
experiments, and not often connefled with
thrilling in the extremities.
( 4^1 )
When troubled with indigeftion, I have been
two or three times unpleafantly afFedled after
the excitement of the gas. Cardialgia, eruc-
tations and unpleafant fulnefs of the head were
produced.
I have often felt very great pleafure when breath-
ing it alone, in darknefs and filence, occupied
only by ideal exiftence. In two or three in dan-
ces when I have breathed it amidft noife, the
fenfe of heafing has been painfully afFefled
even by moderate in^enfity of found. The
light of the fun has fornetimes been difagreeably
dazzling. I have once or twice felt an uneafy
fenfe of tenfion in the cheeks and tranfient'
pains in the teeth.
Whenever I have breathed the gas after ex-
citement from moral or phyfical caufes, the
delight has been often intenfe and fublime.
On May 5th, at night, after walking for an
hour ainidft the fcenery of the Avon, at this
period rendered exquifitely beautiful by bright
moonfhine; my mind being in a ftate of'
( ^92 )
agreeable feeling, I refpired fix quarts of newly
prepared nitrous oxide. ,
The thrilling was very rapidly produced.
The objects around me were perfe^^ly diftindi,
and the light of the candle not as ufual dazzling.
The pleafurable fenfation was at firft local and
perceived in the lips and about the cheeks. It
gradually however, difFufed itfelf over the whole
body, and in the middle of the experiment was
for a moment fo intenfe and pure as to ar/orb
exiftence. At this moment, and not before, I loii
confcioufnefs ; it was however, quickly reftored,
and I endeavoured to makeaby-ftander acquaint-
td with the pleafure I experienced by laughing
and ftamping. ' I had no vivid ideas. Tiie
thrilling and the pleafurable feeling continued
for many minutes ; I felt two hours afterwards,
a flight recurrence of them, in the intermediate
flate between fleeping and waking ; and I had du-
ring the whole of the night, vivid and agrceable
dreams. I awoke in the morning with the
feeling of refllefs energy, or that defireofadlion
connecSted with no definite objedl^ which I had
( 493 )
often experienced in the courfe of experiments
in 1799-
I have two or three times fince refpired ni-
trous oxide under fimilar circumftances ; but
never with equal pleafure.
During the Jaft fortnight, I have breathed
it very often ; the efFedls have been powerful
and the fcnfations uncommon ; but pleafurable
only in a flight degree.
I ought to have obferved that a defire to
breathe the gas is always awakened in me by
the fight of a perfon breathing, or even by that
of an air-bag or an air-holder.
I have this day, June 5th, refpired four large
dofes of gas. The firft two taken in the morn-
ing aded very powerfully ; but produced no
thrilling or other pleafurable feelings. The
efFedls of the third breathed immediately after a
hearty dinner were pleafant, but neither in-
tenfe or intoxicating. The fourth was refpired
at night in darknefs and filence after the occur-
rence of a circumftance w^hich had produced
fome anxiety. This dofe afFc6led me power-
( 494 )
fully and pleaifantly ; a flight thrilling m the
extremities was produced ; an exhilaration con-
tinued for fome time, and I have had but little
return of uneafinefs. 1 1 P. M.
From the nature of the language of feeling,
the preceding detail contains many imperfec-
tions ; I have endeavoured to give as accurate
an account as poffible of the flrange efFedts of
nitrous oxide, by making ufe of terms ftanding
for the mod fimilar common feelings.
We are incapable of recolleiling pleafures
and pains of fenfe.*" It is impoffible to reafon
concerning them, except by means of tercns
which have been aflbciatod with them at the
moment of their exillence, and which are after-
wards called up amidfl: trains of concomitant
ideas.
* Phylical pleafure and pain generally occur conne(5ted
with a compound impreffion, i. e. an organ and fome
objed. When the idea left by the compound irapreflion,
is called up by being linked accidentally to^ fome other
idea or impreffion, no recurrence, or the llighteft poffible,
of the pleafure or pain in any form will take place. But
when the compound impreffion itfclf exifls luithout the
phyfical pleafure or pain, it will awaken ideal or intello6taal
( 405 )
Wlien pleafures and pains are new or oon-
ne(3ed with new ideas, they can never be inteU
ligibly detailed unlcfs aflboiateJ dnriwg their
cxiftence with terms ftanding tor analogous
feelings.
I have fometiimes eiiperienoed from nitrous
oxide, lenfations timilar to no others^ and they
have confequently been Indefcribable. This
has been likewife often the cafe with other
perfons. Of two paralytic patients who were
afked what they felt after breathing nitrous
pleafure or pain, i. e. hope or fear. So that phyfical plea-
fure and pain are to hope and fear, what impreflions
are to ideas. For inllance, alfuming no accidental aflbcia-
tion, the child does not fear the fire before he is burnt.
When he puts his finger to the fire he feels the phyfical
pain of burning, which is connc6ted with a vifible com-
pound iraprcflion, the fire and his finger. Now when the
compound idea of the fire and his finger, left by the com-
pound impreflion are called up by his mother, faying,
*' You have burnt your finger ,' nothing like fear or the pain
of burning is conne6ted witH it. But when the finger is
brought near the fire, i. e. when the compound impreflion
again exifts, the ideal pain of burning or the paflion of fear
is awakened, and it becomes conne6led with thofc very
adtions which removed the finger from the fire.
(496)
oxide, the firft anfwered, ^^ I do not know hoiv^
hit very queer,'* The fecond faid, " I felt like
the found of a harpT Probably in the one cafe, no
analogous feelings had ever occurred. In the
other, the pleafurable thrlings were fimilar to
the fenfations produced by mufic ; and hence,
they were con nedled with terms formerly applied
to mufic.
DIVISION 11.
DETAILS of the EFFECTS produced by the RES-
PIRATION of NITROUS OXIDE upon different
INDIVIDUALS furnished by THEMSELVES.
X HE experiments related in the following
details, were made in the Medical Pneumatic
Inflitution.
AbftracSis from many of them have been
publifhed by Dr. Beddoes.*
I. Detail of Mr. J. W. Toeuv.
Having feen the remarkable efFedis produced
on Mr, Davy, by breathing nitrous oxide, the
18th of April; 1 became defirous of taking fome.
A day or two after I breathed 2 quarts of this
* Notice of fome Obfervations made at the Medical
Pneumatic Inftitution.
Hh
( 498 )
gas, returning it back again into the fame bag,
after two or three infpirations, breathing became
difficult, and I occafionally admitted common
air into my lungs. While the refpiration was
continued, my fenfations became more pleafant.
On taking the bag from my mouth, I ftaggercd
a little, but felt no other efFedl.
On the fecond time of making the experi-
ment, I took nearly four quarts, but ft ill found
it difficult to continue breathing long, though
the air which was left in the bag was far from
being impure.
The eftecSs however, in this cafe, were more
ftriking than in the former. Increafed mufcu-
lar a6tion was accompanied by very pleafurable
feelings, and a ftrong defire to continue the
infpiration. On removing the bag from my
mouth, I laughed, ftaggered, and attempted to
fpeak, but ft:ammered exceedingly, and was
utterly unable to pronounce fome words. My
ufual flate of mind, however, foon returned.
On the 29th, I again breathed four quarts.
The pleafant feelings produced at firft, urged
( m )
tnc to continue the infpiration with great eager-*
nefs. Thefe feelings however, went off towards
the end of the experiment, and no other effects
followed. The gas had probably been breathed
too long, as it would not fupport flame. I then!
propofcd to Mr. Davy, to inhale the air by the
mouth from one bag, and to ey.pire it from the
nofe into another. Thfs method was purfued
with lefs than three quarts, but the efFeds were
fo powerful as to oblige me to take in a little
common air occafionally. I foon found my
nervous fyOem agitated by the higheft fenfa-
iions of pleafure, which are difficult of defcrip-
tion ; my mufcular powers were very much
ihcreafed, and I went on breathing with great
vehemence, not from a difficulty of infpiration,
but from an eager avidity for more air. When
the b^gs were exhaufted and taken from me^
I continued breathing with the fame violence^
then fuddenly flarting from the chair, and vo-
ciferating with pleafure, I made towards thofe
that were prefent, as I wifhed they fhoulcf
participate in my feelings, I jftruck gently at
( 500 )
Mr. Davy and a ftranger entering tlie room at
the moment^ I made towards him, and gave him
feveral blows, but more in the fpirit of good
humour than of anger. I then ran through
different rooms in the houfe, and at laft returned
to the laboratory fomewhat more compofed ;
my fpirits continued much elevated for fome
hours after the experiment, and I felt no con-
fequent depreflion either in the evening or the
day following, but flept as foundly as ufual.
On the 5th of May, I again attempted to
breathe nitrous oxide, but it happened to con-
tain fufpended nitrous vapour which rendered
it non-refpirable.
On the 7th, I infpired 7 quarts of pure gas
mingled with an equal quantity of common air,
the fenfations were pleafant, and my mufcular
power much increafed.
On the 8th, I infpired fire quarts without
any mixture of common air, but the effedls
were not equal to thofe produced the day before ;
Indeed there were reafons for fuppofing that the
gas was impure.
( 501 )
On the 18th, I breathed nearly fix quarts of
the pure nitrous oxide. It is not eafy to de-
fcribe my fenfations ; they were fuperior to any
thing I ever before experienced. My ftep was
firm, and all my mufcular powers increafed.
My fenfes were more al-ive to every furrounding
impreflion ; I threw myfelf into feveral theatri-
cal attitudes, and traverfed the laboratory with
a quick ftep ; my mind was elevated to a mofl:
fublime height. It is giving but a faint idea of
the feelings to fay, that they refembled thofe
produced by a reprefentation of an heroic fcene
on the ftage, or by reading a fublime paflage
in poetry when circumftances contribute to
awaken the fineft fympathies of the foul. In a
few minutes the ufual ftate of mind returned.
I continued in good fpirits for the reft of the
day, and flept foundly.
Since the I8th of May, I have very often
breathed nitrous oxide. In the firft experi-
ments when pure, its effedls were generally
fimilar to thofe juft defcribed.
Lately I have feldom experienced vivid ien«
( 56a )
fations. The pleafure produced by it is iligbt
and tranquil, I rarely feel lublime emotions or
increafed mufcular power.
J. W. TOBIN.
OBoher, 1799-
II. 'Detail of Mr. Wm. Clayfield.
The firft time that I breathed the nitrous
oxide, it produced feelings analogous to thofe of
intoxication. I was for fome time unconfcious
ofexiftence, but at no period of the experiment
experienced agreeable fenfations, a momentary
naufea followed it ; but unconnedled with lan-
guor or head ache.
After this I feveral times refpired the gas, but
on account of the fulnefs in the head and appa-
rent throbbing of the arteries in the brain,*al ways
defifted to breathe before the full efFe(51s were
produced. In two experiments however, when
by powerful voluntary efforts I fucceeded in
breathing a large quantity of gas for fome mi-
* In fome of thefe experiments, hearing was rendered
more acute.
( 503 )
nutes, I had highly pleafurable thrillings in the
extremities, and fuch increafe of mufcular
power, as to be obliged to exert my limbs with
violence. After thefe experiments, no languor
or depreffion followed.
-William Clayfield.
III. Letter from Dr. Kinglake.
In compliance with your defire, I will en-
deavour to give you a faithful detail of the
efFedls produced on^my fenfations by the inha-
lation of nitrous oxide.
My firft infpiration of it was limited to four
quarts, diluted with an equal quantity of atmof-
pheric air. After a few infpirations, a fenfe of
additional freedom and power (call it energy if
you pleafe) agreeably pervaded the region of
the lungs ; this was quickly fucceedcd by an
almofl delirious but highly pleafurable fenfation
in the brain, which was foon diffufed over ih^
whole frame, imparting to the mufcular pow^r
at once an encreafed difpofition and tone for
adion ; but the mental effedl of the excitement
( 504 )
was fuch as to abforb in a fort of intoxicating
placidity, and delight, volition, or rather the
power of voluntary motion. Thefe cffedls were
in a greater or lefs degree protracted during
about five minutes, when the former ftate re-
turned, with the difference however of feeling
more cheerful and alert, for feveral hours after.
It feemed alfo to have hftd the further efFecl
of reviving rheumatic irritations in the fhoulder
and knee-joints, which had not been previoufly
felt for many months. No perceptible change
was induced in the pulfe either at or fubfequent
to the time of inhaling the gas.
The efFedls produced by a fecond trial of its
powers, were more extenfive, and concentrated
on the brain. In this inflance, nearly fix quarts
undiluted, were accurately and fully inhaled.
As on the former occafion, it immediately proved
agreeably refpirable, but before the whole quan-
tity was quite cxhauficd, its agency was exerted
fo flrongly on the brain, as progrefTively to fuf-
pend the fenfes of feeing, hearing, feeling, apd
ultimately the power of volition itfclf. At this
( 505 )
period, the pulfe was much augmented both in
force and frequency ; flight convulfive twitches
of the mufcles of the arms were alfo induced ;
no painful fenfation, naufea, or languor, how-
ever, either preceded, accompanied, or followed
this (late, nor did a minute elapfe before the
brain rallied, and refumed its wonted faculties,
when a fenfe of glowing warmth extending over
the fyftem, was fpe^diiy fucceeded by a re-in-
ftatement of the equilibrium of health.
The more permanent effects were (as in the
firft experiment) an invigorated feel of vital
power, improved fpirits, tranfient irritations in
different parts, but not fo charafieriflically rheu-
matic as in the former inftance.
Among the circumftances mofi; worthy of
regard in confidering the properties and ad-
miniflration of this powerful aerial agent, may
be ranked, the fdS. of its being (contrary to the
prevailing opinion*) both highly refpirablc, and
* Dr. Mitchill (an Amcricnn Chemift) Ims erroneoiifl/
fapplbfed its full admilfion to the Inngs, in its concentrated
Itate, to be incompatible with animal life, and that in a
aiore diluted form it operates ns a principal agent in the
( 5o6 ) ■
falutary, that it impreffes the brain and fyftem
at large with a more or lefs ftrong and durable
degree of pleafurable fenfation, that unlike the
, effedl of other violently exciting agents, no fen-
fible exhauftion or diminution of vital power
accrues from the exertions of its ftimulant pro-
perty, that its mod excefuve operation even,
is neither permanently nor tranfiently debilita-
ting ; and finally, that it fairly promifes under
judicious application, to prove an extremely
efficient remedy, as well in the vaft tribe of
difeafes originating from deficient irritability
and fenfibility, as in thofe proceeding from
morbid affociat ions, and modifications, of thofe
vital principles.
produ£lion of contagious difeafes, &c. This gratuitous
pofition is thus unqualifiedly affirmed. '^ If a full infpira-
" tion of gafeous oxyd be made, there will be a fuddcn
" extin6lion of life j and this accordingly accounts for the
" faa related by RufTel (Hiftory of Aleppo, p. 232.) and
'^ confirmed by other obfervers, of many perfons falling
" down dead fuddenly, when ftruck with the contagion of
*' the plague."
Vide Remarks on the Gafeous Oxyd of Azote, by Saitiuel
Latham Mitchill, M. D.
( 507 )
If you ftiould deem any thing contained in
this curfory narrative capable of fubferving in
any degree the practical advantages likely to
refult from your fcientific and valuable invefti-
gation of the genuine properties of the nitrous
oxide^ it is perfedly at your difpofal.
I am
Your fincere friend,
Robert Kinglake.
Briftoly June ]4tb, 1799.
To Mr. Davy.
IV. Detail of Mr. Southey.
In breathing the nitrous oxide, I could not
didinguifh between the firft feelings itoccafioned
and an apprehenfion of which I was unable to
diveft myfelf. My firft definite fenfation was a
dizzinefs, a fulnefs in the head, fuch as to in-
duce a fear of falling. This was momentary.
When I took the bag from my mouth, I im-
mediately laughed. The laugh was involuntary
< 506 )
but highly pleafurable, accompanied by a thrill
all through me ; and a tingling in my toes and
fingers, a fenfation perfeflly new and delight-
ful. I felt a fulnefs in my chefl afterwards ;
and during the remainder of the day, imagined
that my tafte and hearing were more than com-
monly quick. Certain I am that I felt myfelf
more than ufually ftrong and chearful.
In a fecond trial, by continuing the inhala-
tion longer, I felt a thrill in my teeth ; and
breathing ilill longer the third time, became fo
full of ftrength as to be compelled to exercife
my arms and feet.
Now after an interval of fome months, during
which my health has been materially impaired,
the nitrous oxide produces an effedl upon me
totally different. Half the quantity affeds me,
and its operation is more violent ; a flight laugh-
ter is firft induced,* and a defire to continue the
* In the former experiments, Mr. Sonthey generally
refpired fix quarts^ now he is unable to confnme two.
In an experiment made fince this paper was drawn up,
the efFed was rather pleafurable.
( 509 )
inhalation, which is counteracted by fear from
the rapidity of refpiration ; indeed my breath
beconnes fo fhort and quick, that I have no doubt
but the quantity which I formerly breathed,
would now deftroy me. The fenfation is not
painful, neither is it in the flightefl: degree
pleafurable.
* Robert Southey.
V. Letter from Dr. Roget.
The ciFecS of the firft infpiratrons of the ni-
trous oxide was that of making me vertiginous,
and producing a tingling fenfation in my hands
and feet : as thefe feelings increafed, I feemed
to lofe the fenfe of my own weight, and imagined
1 was finking into the ground. 1 then felt a
drowfinefs gradually fteal upon me, and a dif-
inclination to motion ; even the adions of
infpiring and expiring were not performed
without effort : and it alfo required fome atten-
tion of mind to keep my noftrils clofed with my
fingers. I was gradually roufed from this tor-
( 510 )
por by a kind of delirium, which came on fo
rapidly that the air-bag dropt from my hands.
This fenfation increafed for about a minute
after I had ceafed to breathe, to a much greater
degree than before, and I fuddenly loft fight of
all the obje(5\s around me, they being appa-
rently obfcured by clouds, in which were many
luminous points, fimilar to what is often expe-
rienced on rifing fuddenly and ftretching out
the arms, after fitting long in one pofition.
I felt myfelf totally incapable of fpeaking,
and for fome time loft all eonfcioufnefs of where
I was, or who was near me. My whole frame
felt as if violently agitated : I thought I panted
violently : my heart feemed to palpitate, and
every artery to throb with violence ; I felt a
finging in my ears ; all the vital motions
feemed to be irrefiftibly hurried on, as if their
equilibrium had been deftroyed, and every
thing was running headlong into confufion.
My ideas fucceedcd one another with extreme
rapidity, thoughts rufhed like a torrent through
my mind, as if their velocity had been fuddenly
( 511 )
accelerated by the burfting of a barrier which
had before retained them in their natural and
equable courfe. This ftate of extreme hurry,
agitation, and tumult, was but tranfient. Every
unnatural fenfation gradually fublided ; and in
about a quarter of an hour after I had ceafed
to breathe the gas, I was nearly in the fame
flate in which I had been at the commence-
ment of the experiment.
I cannot remember that I experienced the
lead pleafure from any of thefe fenfations. I
can however, eafily conceive, that by frequent
repetition I might reconcile myfelf to them,
and pofRbly even receive pleafure from the
fame fenfations which were then unpleafant,
I am fenfible that the account I have been
able to give of my feelings is very imperfe<3.
For however calculated their violence and
novelty were to leave a lading impreffion on
the memory, thefe circumltances were for that
very reafon unfavourable to accuracy of com-
parifon with fenfations already familiar.
The nature of the fenfations themfelves.
( 512 )
which bore greater refemblance to a half deli-
rious dream than to any diftindl ftate of mind
capable of being accurately remembered, con-
tributes very much to increafe the difficulty.
And as it is above two months fince I made the
experiment, many of the minuter circumtlan-
ces have probably cfcaped me.
I remain
Yours, &c.
P. IIOGET.
To Mr. Davy.
VI. Letter from Mr. James Thomson.
The firft time I refpired nitrous oxide, the
experiment v^^as made under a flrong impreffion
of fear, and the quantity I breathed not fuffi-
cient, as you informed me, to produce the
ufual efFe6l. I did not note very accurately my
fenfations. I remember I experienced a flight
degree of vertigo after the third or fourth
infpiration ; and breathed with increafed vigor,
my infpirations being much deeper and more
( 513 )
Vehement than ordinary. I was enabled the
next time I made the experiment, to attend
more accurately to my fenfations, and you have
the oblervations I made on them at the time.
After the fourth infpiration, I experienced
the fame increafed a6iion of the lungs, as in
the former cafe. My infpirations became un-
commonly full and ftrong, attended with a
thrilling fenfation about the cheft_> highly plea-
furable, which increafed to fuch a degree as to
induce a fit of involuntary laughter, which I in
vain endeavoured to I'eprefs. I felt a flight
giddinefs which lafted for a few moments only.
My infpirations now became more vehement
and frequent ; and I inhaled the air with an
avidity ftrongly indicative of the pleafure I
received. That peculiar thrill which I had at
firfl experienced at the cheft, now pervaded
iTiy whole frame ; and during the two or three
laft infpirations, was attended w^ith a remarkable
tingling in my fingers and toes. My feelings
at this moment are not to be defcribed ; I felt a
h igh, an extraordi nary degree of pleafure, different
I i
( 514 )
from that produced by wine, being divefied of all
its grofs accompaniments, and yet approaching
nearer to it than to any other fenfation I am
acquainted with.
I am certain that my mufcular firength was
for a time much increafed. My difpofitlon to
exert it was fuch as I could not reprefs, and the
fatisfadtion I felt in any violent exertion of my
legs and arms is hardly to be conceived. Thefe
vivid fenfations were not of long duration ; they
diminifhed infenfibly, and in little more than a
quarter of an hour I could perceive no differ-
ence between the ftate I was then in, and that
previous to the refpiration of the air.
The obfcrvations I made on repeating the
experiment, do not differ from the preceding,
except in the circumflance of the involuntary
laughter, which I never afterwards experienced,
though I breathed the air feveral times ; and in
the following curious fa(^, which, as it was de-
pendent on circumfiances, did not always occur.
Having refpired the fame quantity of air as
ufual, and with precifely the fame efFedls, I
(515 )
was furprifcd to find niyfelf afFc^led a few mi-
nutes afterwards with the recurrence of a pain
in my back and knees, which I had experienced
the preceding day from fatigue in walking. I
was rather inclined to deem this an accidental
coincidence than an ciYe6\ of the air; but the
fame thing confiantly Dccurring whenever I
breathed the air, fhortly after fuffering paim
cither from fitigue, or any other accidental
caufe, left no doubt on my mind as to the
accuracy of the obfervation.
I have now given you the fubdance of the
notes I made whilft the impreflions were ftrong
on my mind. I cannot add any thing from
recolledlion that will at all add to the accuracy
of this account, or affiil; thofe who have not
refpired this air, in forming a clearer idea of its
extraordinary effcdis. It is extremely difficult
to convey to others by means of words, any
idea of particular fenfations, of which they have
had no experience. It can only be done by
making ufe of fuch terms as are expreffive of
fenfations that refemble them, and in thefe our
(516)
vocabulary Is very defedlive. To be able at all
to comprehend the efFcds of nitrous oxide, it
is neceffary to refpire it, and after that, wc muft
either invent new terms to exprefs thefe new
and particular fenfations, or attach new ideas to
old ones, before we can communicate intelligi-
bly with e<ich other on the operation of this
extraordinary gas.
I am &c.
James Thomson-
London^ Sept, 21, 1799.
To Mr. Davy.
VII, Detail of Mr. Coleridge.
The firft time I infpired the nitrous oxide, I
felt an highly pleafurable fenfation of warmth
over my whole frame, refembling that which
I remember once to have experienced after
returning from a walk in the fnow into a warm
room. The only motion which I felt inclined
to make, was that of laughing at thofe who
were looking at me. My eyes felt diftended,
(517)
and towards the laft, my heart beat as if it were
leaping up and down. On removing the mouth-
piece the whole fenfation went off almoft
inftantly.
The fecond time, I felt the fame pleafurable
fenfation of warmth, but not I think, in quite
fo great a degree. I wiftied to know what efFedt
it would have on my impreffions ; I fixed my
eye on fome trees in the diftance, but I did
not find any other efFed except that they be-
came dimmer and dimmer, and looked at laft
as if I had feen them through tears. My heart
beat more violently than the firft time. This
was after a hearty dinner.
The third time I was more violently atSled
on than in the two former. Towards the laft,
I could not avoid, nor indeed felt any wifh to
avoid, beating the ground with my feet ; and
after the mouth-piece was removed, I remained
for a few feconds motionlefs, in great extacy.
The fourth time was immediately after break-
fafl:. The few firft infpirations afFecled me fo
little that I thought Mr, Davy had given me
( 518 ) -
atmofpberlc air : but foon felt the warmth be-
ginning about my cheft, and fprcading upward
and downward, fo that I could feci its progrefs
over my whole frame. My heart did not beat
fo violently ; my fenfations were highly plea-
furable, not fo intenfe or apparently local, but
of more unmingled pleafure than I had ever
before experienced. *"
S. T. Coleridge.
VIII. Detail of Mr. Wedgwood.
July 23, I called on Mr. Davy at the Medi-
cal Inflitution, who aiked me to breathe fome
of the nitrous oxide, to which I confented,
being rather a fceptic as to its effe6ls, never
having feen any perfon afFed^ed. I firft breathed
about fix quarts of air which proved to be only
common atmofpheric air, and which confe-
quently produced no effect.
I then had 6 quarts of the oxide given me in
* The dofes in thcfe experiments were from iive to
feven quarts.
( 519 )
a bag undiluted, and as foon as I had breathed
three or four refpirations, I felt myfelf afFedled
and my refpiration hurried, which efFedl increa-
fed rapidly until I became as it were entranced,
when I threw the bag from me and kept breath-
ing on furioufly with an open mouth and hold-
ing my nofe with my left hand, having no
power to take it away though aware of the
ridiculoufnefs of my lituation. Though appa-
rently deprived of all voluntary motion, I was
fenfible of all that palTed, and heard every thing
that was faid ; but the moft fingukr fenfation
I had, I feel it impoffibJe accurately to defcribe.
It was as if all the mufcles of the body were
put into a violent vibratory motion ; I had a very
ilrong inclination to make odd antic motions
with my hands and feet. When the firfl flrong
fenfations went off, I felt as4f I were lighter than
the atmofphere, and as if I was going to mount
to the top of the room. I had a metallic tafte
left in my mouth, which foon went off.
Before I breathed the air, I felt a good deal
fatigued from a very long ride I had' had the
( 520 )
day before, bat after breathing, I loft all fen fe
of fatigue.
IX. Detail of Mr. George Burnet,
I had never heard of the effects of the nitrous
oxide, when T breathed fix quarts of it. 1 felt
a delicious tremor of nerve, which was rapidly
propagated over the whole nervous fyflem. As
the adlion of inhaling proceeds, an irrefiftible
appetite to repeat it is excited. There is now a
general fwell of fenfations, vivid, flrong, and
inconceivably pleafurable. They ilill become
more vigorous and glowing till they are com-
municated to the brain, wjien an ardent flufh
overfpreads the face. At this moment the tube
inferted in the air-bag was taken from my
mouth, or I muft have fainted in extacy.
The operation being over, the ftrength and
turbulence of my fenfations fubfided. To this
fucceeded a ftate of feeling uncommonly ferene
and tranquil. Every nerve being gently agita-
( 521 )
ted with a lively enjoyment. It was natural to
expedl that the efFe6l of this experiment, would
eventually prove debilitating. So far from this
I continued in a ftate of high excitement the
remainder of the day after two o'clock, the
time of the experiment, and experienced a flow
of fpirits not merely chearful, but unufually
joyous,
George Burnet.
X. Detail of Mr. T. Pople.
A difagreeable fenfation as if breaking out
into a profufe perfpiration, tenfion of the tym-
panum, cheeks and forehead ; almofl total
lofs of mufcular power; afterwards increafed
povv'crs both of body and mind, very vivid fenla-
tions and highly pleafurable. Thofe pleafant
feelings were not new, thiey were felt, but in a
lefs degree, on afcending fome high mountains
in Glamorgan fliire.
On taking it the fecond time, there was a
difagreeable feeling about the face. In a {qw;
( ^'22 )
feconds, the feelings became pleafunible ; all
the faculties abforbed by the fine pleafing feel-
ings of exiflence without confcioufnefs ; an
involuntary burft of laughter.
Thomas Pople.
XL Detail of Mr. Hammick,
Having never heard any thing of the mode
of operation of nitrous oxide, I breathed gas in
a filk bag for fome time, and found no efFefls,
but oppreffion of refpiration. Afterwards Mr.
Davy told me that I had been breathing atmof-
pheric air.
In a fecond experiment made without know-
ing what gas was in the bag, I had not breathed
half a minute, when from the extreme pleafure
I felt, I unconcioully removed the bag from
my mouth ; but when Mr. Davy offered to take
it from me, I refufed to let him have it, and
faid eagerly, " let me breathe it again, it is
highly pleafant ! it is the ftrongeft ftimulant I
ever felt !" I was cold when I began to refpirc,
( 523 )
but had immediately a pleafant glow extending
to my toes and fingers. I experienced from the
air a pleafant tade which I can only call fweetly
aftringent ; it continued for fome time : the
fenfe of exhilaration was lading. This air Mr.
Davy told me was nitrous oxide.
In another experiment, when I breathed a
fmall dofe of nitrous oxide, the efFedls were
flight, and fometime afterwards I felt an unufual
yawning and languor.
The laft time that I breathed the gas, the
feelings were the mod pleafurable I ever expe-
rienced ; my head appeared light, there was a
great warmth in the back and a general unufual
glow ; the tafte was diftinguifliable for fome
time as in the former experiment. My ideas
were more vivid, and followed the natural
order of aflbciation. I could not refrain from
mufcular adion.
Stephj5:n Hammick, Junr.
Sept. 15th.
( 524 )
XII. Detail of Dr. Blake.
Dr. Blake inhaled about fix quarts of the
air, was afFe6led during the procefs of refpiring
it wi^h a flight degree of vertigo, which was
almoft immediately fucceedcd by a thrilling
fenfation extending even to the extremities,
accompanied by a mod happy (late of mind and
highly pleafurable ideas. He felt a great propen-
fity to laugh, and his behaviour in fome mea-
fure appeared ludicrous to thofe around him.
Mufcular power feemed agreeably increafed,
the pulfe acquired ftrength and firmnefs, but
its frequency was fomewhat diminifhed. He
perceived rather an unpleafant tafte in the
mouth and about the fauces for fome hours
afterwards, but in every other refpedl, his feel-
ings were comfortable during the remainder of
the day.
December^ 30th,
To Mr. Davy.
( 525 )
XIII. Detail of Mr. Wansey.
I breathed the gas out of a filk bag, believing
it to be nitrous oxide, and was much furprifed
to find that it produced no fenfations. After
the experiment, Mr. Davy told me it was com-
mon air.
I then breathed a mixture of common air
and nitrous oxide. I felt a kind of intoxica-
tion in the middle of the experiment, and
Hopping to cxprefs this, deftroyed any farther
efFedls.
I now breathed pure nitrous oxide ; the efFedl
was gradual, and I at firft experienced fulnefs
in the head, and afterwards fenfations fo de-
lightful*, that I can compare them to no others,
except thofe which I felt (being a lover of mufic)
about five years fince in Weilminfter Abbey,
in fome of the grand chorufTes in the Meffiah,
from the united powers of 700 inftruments of
mufic. I continued exhilarated throughout the
day, flept at night remarkably found, and ex~
( 326 )
perienced when I awoke in the morning, a
recurrence of pleafing fenfation.
In another experiment, the effed was ftill
greater, the pulfe was rendered fuller and
quicker, I felt a fenfe of throbbing in the head
with highly pleafurable thrill ings all over the
frame. The new feelings were at laft fo power-
ful as to abforb all perception. I diflinguifhed
during and after the experiment, a tafte on the
tongue, like that produced by the contact of
zinc and filver.
Henry Wansey.
XIV. Deiail of Mr. Rickman.
On inhaling about fix quarts, the firft altered
feeling was a tingling in the elbows not unlike
the efFed of a flight eledric fl:iock. Soon after-
wards, an involuntary and provoking dizzinefs
as in drunkennefs. Towards the clofc of the
inhalation, this fymptom decreafcd ; though the
nofe was flill involuntary held faft after the air-
bag was removed. The dofe was probably an
( 527 )
undercharge, as no extraordinary fenfation was
felt more than half a minute after the inhalation.
J. RiCKMAN.
XV. Detail of Mr. Lgvell Edgworth.
My firft fenfation was an univerfal and con-
liderable tremor. I then perceived fome giddi-
nefs in my head, and a violent dizzinefs in my
fight ; thofe fenfations by degrees fubiided, and
I felt a great propenfity to bite through the
wooden mouth-piece, or the tube of the bag
through which I infpired the air. After I had
breathed all the air that was in the bag, I
eagerly wifhed for more. I then felt a flrong
propenfity to laugh, and did burft into a violent
fit of laughter, and capered about the room
without having the power of reftraining myfelf.
By degrees thefe feelings fubfided, except the
tremor which lafled for an hour after I had
breathed the air, and I felt a vveaknels in my
knees. The principal feeling through the whole
of the time, or what I fhould call the character-
( 526 )
iflical part of the eftedl, was a total difficulty of
reftralning my feelings, both corporeal and
mental, or in other words, not having any
command of one'self.
XVI. Detail of Mr. G. Bedford.
I inhaled 6 quarts. Experienced a fenfatiorl
of fulnefs in the extremities and in the face^
with a defire and power of expaniion of the
lungs very pleafurable. Feelings iimilar to
intoxication were produced, without being dif-
agreeable. When the bag was taken away, an
involuntary though agreeable laughter took
place, and the extremities were warm.
In about a quarter of an hour after the above
experiment, I inhaled 8 quarts. The warmth
and fulnefs of the face and extremities were
fooner produced during the infpiration. The
candle and the perfons about me, afTumed the
fame appearances as took place during the efFedl
produced by wine, and I could perceive no
( 529 )
determinate outline. The defire and power to
expand the lungs was increafed beyond that in
the former experiment, and the whole body and
limbs Teemed dilated without the fenfe of teaiion,
it was as if the bulk was increafed without any
addition to the fpecifiii gravity of the body,
which was highly pleafant. The provocation
to laughter was not fo great as in the former
experiment, and when the bag was removed,
the warmth almoft fuddenly gave place to a
coldnefs of the extremities, particularly of the
hands which were the firil to become warm
during the infpiration. A flight fenfation of
fulnefs not amounting to pain in the head, has
continued for fome minutes. After the firfi:
experiment, a fenfation in the wrifts and elbows
took place, fimilar to that produced by the
electric (hock.
G. C. BEDFORt),
March 30th, 1800.
Kk
( 530 )
XVII. Detail of Miss Ryland.
After having breathed five quarts of gas, I
experienced for a (hort time a quicknefs and
difficulty of breathing, which was fucceeded by
extreme languor, refembling fainting, without
the very unpleafant fenfation with which it is
ufually attended. It entirely deprived me of
the power of fpeaking, but not of recollection,
for I heard every thing that was faid in the room
during the time ; and Mr. Davy's remark " that
my pulfe was very quick and full." When the
languor began to fubfide, it was fucceeded by
reftlefsnefs, accompanied by involuntary muf-
cular motions. I was warmer than ufual, and
very fleepy for feveral hours.
XVIII. Letter from Mr. M. M. Coates.
I will, as you requeft, endeavour to defcribe
to you the efFedl produced on me laft Sunday
fe'pnight by the nitrous oxide, and will at the
( ^31 )
fame time tell you what was the previous ftate
of my mind on the fubjedi.
When I fat down to breathe the gas, I believed
that it owed much of its efFedl to the predifpo-
fing agency of the imagination, and had no
expectation of its fenfible influence on myfelf.
Having ignorantly breathed a bag of common
air without any effect, my doubts then arofe
to pofitive unbelief.
After a few infpirations of the nitrous oxide,
I felt a fulnefs in my head, which increafed
with each inhalation, until, experiencing fymp-
toms which I thought indicated approaching
fainting, I ceafed to breathe it, and was then
confirmed in my belief of its inability to pro-
duce in me any pleafurable fenfation.
But after a few feconds, I felt an immoderate
flow of fpirits, and an irrefiftible propenfity to
violent laughter and dancing, which, being fully
confcious of the violence of my feelings, and of
their irrational exhibition, I made great but
inefFedual efforts to reftrain ; this was my ftate
for feveral minutes. During the refl of the day,
( 532 )
I experienced a degree of hilarity altogether
new to roe. For fix or feven days afterwards,
I Teemed to feel moft exquifitely at every nerve,
and was much indifpofed to my fedentarj^ pur-
fuits ; this acute fenfibility has been gradually
diminifhing ; but I flill feel fomewbat of the
efiedb of this nof el agent.
Your's truly,
To Mr. Datt. M. M. Coated,
June lUb, 1800.
DIVISION III.
ABSTRACTS from ADDITIONAL DETAILS,-
OBSERVATIONS on the EFFECTS of NITROUS
OXIDE, by Dr. BEDDOES.^CONCLUSION.
I. AbstraSfs from additional Details,
JL HE trials related in the following abftrads,
have been chiefly made fince the publication
of Dr. Beddoes's Notice. Many of the indivi-
duals breathed the gas from pure curiofity.
Others with a difbelief of its powers.
Mr. Wynne^ M. p. breathed five quarts of
diluted nitrous oxide, without any fenfation.
Six quarts produced fulnefs in the chefl,
heat in the hands and feet, and fenfe of tenfion
in the fingers, flight but pleafant fenfations.
Seven quarts produced no new or different
efFedts.
( 534 )
Mr. Mackintosh feveral times breathed
nitrous oxide. He had fenfe of fulnefs in the
head, thrillings, tingling in the fingers, and
generally pleafurable feelings.
Mr. John Cave, Junr. from breathing four
quarts of nitrous oxide, felt fenfations as from
fuperior wine, and general pleafant feelings.
Mr. Michael Castle, from five quarts,
experienced fenfations of heat and thrilling,
general fpirits heightened confiderably as from
wine ; afterwards, flight pain in the back of the
head.
Mr. H. Card WELL, from five quarts, had
feelings fo pleafurable as almoft to deftroy
confcioufnefs ; almoft convulfed with laugh-
ter; for a long time could not think of the
feeling without laughing ; fenfation of light-
nefs for fome time after.
Mr. Jarman, from five quarts, great plea-
fure, laughter, certainly better fpirits, glow in
the cheeks which continued long.
( 535 )
The gentleman who furnifhed the preceding
detail, had heard of the efFedts of nitrous oxide^
and was prepared to experience new fenfations;
I therefore gave him a bag of common air
which he refpired, believing it to be nitrous
oxide ; and was much furprifed that no efFeds
were produced. He then breathed five quarts
of nitrous oxide, and after the experiment, gave
this account of his fenfations.
Rev. W. A. Canb, after inhaling the gas^
felt the mofl delicious ienfations accompanied
by a thrill through every part of his body. He
did not think it poffible fo charming an efFedl
could have been produced. He had heard of
the gas ; but the refult of the experiment far
exceeded his expe6lations.
May Qth, 1800.
Mr. Joseph Priestley from breathing
nitrous oxide, generally had unpleafant fulnefs
of the head and throbbing of the arteries, which
prevented him from continuing the refpiration*
( 536 )
Dr. Beddoes mentioned in his Notice, that
Mr. JosiAH Wedgwood and Mr. Thomas
Wedgwood, experienced rather unpleafant
feelings from the gas. Mr. Josiah Wedg-
wood has fince repeated the trial, the efFe6ls
were powerful, but not in the flighted degree
pleafhnt.
Mr. R. BouLTON and Mr. G. Watt have
been much lefs afFedled than any individuals.
Many other perfons have refpired the gas,
but as their accounts contain nothing unnoticed
in the details, it is ufelefs to particularife them,
The cafes of all the males who have been un-
pleafantly affefled fince we have learnt to prepare
the gas with accuracy, are related in this Sedlion
and in the laft Divifion. Thofe who have been
pleafurably afFefled after a fair trial and whofe
cafes are not noticed, generally experienced
fulnefs in the head, heat in the cheft, pleafura-
ble thrillings, and confequent exhilaration.
To perfons who have been unaccuflomed to
breathethroughatube^we have ufually given com-
mon air till they have learnt to rcfpire with accu-
( S37 )
racy: and in cafes where the form ofthe mouth has
prevented the lips from being accurately clofed
on the breathing tube^ by the advice of Mr.
Watt, we have ufed a tin plate conical mouth-
piece fixed to the cheeks, and accurately adapted
to the lips ; by means of which precautions, all
our later trials have been perfe<^ly conclufive.
IL Of the effeBs of Nitrous Oxide upon perfons
inclined to hyjierical and nervous affeSfions.
The cafe of Mifs N. and other cafes,
detailed by Dr. Beddoes in his Notice, feemed
to prove that the a6lion of nitrous oxide was
capable of producing hyfterical and nervous
affedlions in delicate and irritable confti-
tutions.
On this fubje61, we have lately acquired
additional fafls.
Mifs E. a young lady who had been fubje<?t
to hyfteric fits, breathed three quarts of nitrous
oxide mingled with much common air, and
( 538 )
felt no efFefls but a flight tendency to fainting.
She then breathed four quarts of pure nitrous
oxide : her firfl infpirations were deep, her
laft very feeble. . At the end (he dropt the bag
from her lips, and continued for fome moments
motionlefs. Her pulfe which at the beginning
of the experiment was ftrong, appeared to me
to be at this time, quicker and weaker. She
foon began to move her hands and talked for
fome minutes incoherently, as if ignorant of
what had pafTed. In lefs than a quarter of an
hour, (he had recovered, but could give no
account of her fenfations. A certain degree of
languor continued through the day.
A young lady who never had hyfterical
attacks, willied to breathe the gas. I informed
her of the difagreeable efFe6ls it had fome-
timcs produced, and advifcd her if fhe had
the flighteft tendency to nervous affedlion,
not to make the trial. She perfifted in her
refolution.
To afcertain the influence of imagination,
f 539 )
I firft gave her a bag of common air, which
fhe declared produced no efFedl. I then or-
dered for her a quart of nitrous oxide mingled
with two quarts of common air ; but from the
miftake of the perfon who prepared it^ three
quarts of nitrous oxide were adminiftered with
one of common air. She breathed this for near
a minute, and after the experiment, defcribed
her fenfations as unpleafant, and faid fhe felt
at the moment as if fhe was dying. The un-
pleafant feelings quickly went off, and a few
minutes after, fhe had apparently recovered
her former ftate of mind. In the courfe of the
day, however, a violent head- ache came on,
and in the evening after (he had taken a medi-
cine which operated violently, hyflerical affec-
tions were produced, followed by great debility.
They occafionally returned for many days, and
fhe continued weak and debilitated for a great
length of time.
Mrs. S. a delicate lady, liable to nervous
afFedlions who had heard of the cafes juft de-
( 540 )
tailed, chofe to breathe the gas. By three
quarts {he .was thrown into a trance, which
lafted for three or four minutes. On recover-
ing, fhe could give no account of her feelings,
and had fbme languor for half an hour after-
wards,
Thefe phsenomena have rendered us cautious
in adminiftering the gas to delicate females.
In a few inftances however, it has been taken
by perfons of this clafs, and even by thofe in-
clined to hyfterical and nervous complaints
with pleafurable efFedls,
Mifs L. a young lady who had formerly had
hyfterical fits, breathed a quart of nitrous oxide
with three quarts of common air without efFedts.
Two quarts of nitrous oxide with one of com-
mon air produced a flight giddinefs ; four quarts
of nitrous oxide produced a fit of immoderate
laughter, which was fucceeded by flight
exhilaration, her fpirits were good through-
out the day, and no depreflion followed.
( 54-2 )
the benefit it confers on fome of the paralytic^
and the injury it does or threatens to the hyfte-
rical and the exquifitely fenfible. I find that
five or Cix quarts operate as powerfully as ever.
I feem to make a given quantity go farther by
holding my breath fo that the gas may be ab-
forbed in a great degree without returning into
the bag, and therefore, be as little heated be-
fore infpiration as poffible. — This may be fancy.
After innumerable trials, I have never once
felt laffitude or depreflion^ Mod commonly
* Of the fa6ts on which Brown founded his law of In-
dire6l debility, no prudent man will lofe fight either in
pra6tifing or Undying medicine. They are incontroverti-
ble.— And our new fa6ts may doubtlefe be conciliated to
the Brunonian do^Iitrine.
But to fuppofe that the expenditure of a quality of a fub-
itance or a fpirit, and its renewal or accumulation are the
general principles of animal phaenomena, fcems tomea griev^-
ous and baneful error. I believe it often happens that excite-
ment and excitability increafe, and that they oftener decreafe
together J — In ihort, without generalizing in a manner, of
which Brown and limilar theories had no conception, our
notions of the living world will in my opinion, continue
to be as confufed as the elements are faid to have been in
chaos. On fome future occafion, I may prefume to point
( 541 )
Mifs B. Y and Mifs S. T ^ both
ddicate but healthy young ladies, were afFeded
very pleafantly ; each by three quarts of nitrous
oxide, the lirft time of refpiring it. Mifs B
Y continued exhilarated and in high fpi-
rits for fome hours after the dofe. Mifs S. Y —
had a flight head-ache, which did not go off
for fome hours.
Mrs. F. inclined to be hyfteri6al, breathed
four quarts of nitrous oxide mingled with com-
mon air. She was giddy and defcribed her
feelings as odd ; but had not the flighted lan-
guor after the experiment,
III. Obfervations on the effects of Nitrous
Oxide ^ by Dr. Bed does.
Neither my notes nor my rccollecStion fupply
much in addition to what I formerly flated in
the Notice of Obfervations nt the Pneumatic
Tnjiitulion, Longman, The gas maintains its
firft charatfler as w€ll in its efFeds on me, as in
( 543 )
I am fenfible of a grateful glow circum praeor--
dm. This has continued for hours.— In two or
three inflances only has exhalation failed to be
followed by pleafurable feeling, it has never been
followed by the contrary. On a few occafions
before the gas was exhaufted, I have found it
impoffible to continue breathing.
The pulfe at firfi: becomes fuller and fbronger.
Whenever, after expofure to a cold wind, the
warmth of the room has created a glow in the
cheeks, the gas has increafed this to ftrong
flufhing — which common air breathed in the
fame way, failed lo do.
Several times I have found that a cut which
had ceafed to be painful has fmarted afrefh, and
on taking two dofes in fucceffion, the fmarting
ceafed in the interval and returned during the
fecond refpiration. I had no previous cxpefla-
tion of the firft fmarting.
out the region through which I imagine the path to wind,
that will lead the obfervers of fome diflant generation to a
point, whence they may enjoy a view of the fubtle, bufy
and intricate movements of the organic creation as clear as
Newton obtained of the movements of the heavenly raaifes.
( 544 )
The only time I was near rendering rhyfelf*
infenfible to prefent objedls by very carefully
breathing feveral dofes in quick fucceffion, I
forcibly exclaimed, tones 1— In fa61, befides
a general thrilling, there feemed to be quick
and ftrong alterations iti the degree of illumi-
nation of all furrounding objedls ; and I felt as
if compofed of finely vibrating firings. On this
occafion, the fkin feemed in a flate of con-
flriflion and the lips glued to the mouth-piece,
and the mucous membrane of the lungs con-
tracted, but not painfully. However, no con-
ftridlion or corrugation of the fkin could be
feen. I am confcious of having made a great
number of obfervations while breathing, which I
could never recover.
Immediately afterwards I have often caught
myfelf walking with a hurried fiep and bufy in
foliloquy. The condition of general fenfation
being as while hearing chearful mufic, or after
good news, or a moderate quantity of wine.
Mr. John Cave, Junr. and his three friends,
as well as others, compared the efFeds to Cham-
( 545 )
pagne. Moft perfons have had the idea of the
ef¥ef\ of fermented iiqaors excited by the gas.
It were to be wifhed that we had, for a fiandard
of comparifon, obfervations on the effedt of
thefe liquors as diverfified and as accurate as
we have obtained concerning the gas ; nor would
more uniformity in the a6lion of thefe fub-
ilances be obferved if the enquiry were
itri6ily purfued. Opium and fpirits feem, iqi
particular dates to (icken and diilrefs in the
firft inftance ; how differently does wine
at an early hour and fatting adi upon thofe
who are accuftomed to take it only after dinner I
I thought it might be an amufing fpe6!acle
to fee the different tints of blood flowing from
a wound by a leech in confequence of breathing
different airs. The purple from the nitrous
oxide was very evident. Oxygene, we thought,
occafioned a quicker fiow and brighter color in
the blood. In another experiment, an inflamed
area round the punciure from a leech applied the
day before^ was judged by feveral fpe<?tators to
become much more crimfon on the refpiration of
L 1
( 546 )
about 20 quarts of oxygene gas, which poffibly
adls more powerfully on inflamed parts.'*' Thefe
and many iimilar experiments, require to be re-
peated on the blood of fingle arteries opened in
warm and cold animals.
It has appeared to me that I could bold my
breath uncommonly long when refpiring oxy-
gene gas rnixed with nitrous oxide. While
trying this to-day, (17th June)^ I thought the
fenfeoffmell much more acute after the ni-
trous oxide than before I began to refpire at
all ; and then I felt confcious that this increafed
acutenefs had before repeatedly occurred — a
* After writing this, I was prefent when an invalid, in
whofe foot the gout, after much wandering, had at laft fixed,
breathed 12 quarts of oxygene gas. While breathing, he
eagerly pointed to the inflamed leg ; and afterwards faid he
had felt in it a new fenfation, fomewhat like tenlion. — I
never had feen oxygene refpired where there was fo much
local inflammation.
June 18. After four quarts of oxygene with 6 of nitrous
oxide and then 6 of nitrous oxide alone, violent itching of
the wounds made by the leech ; and rednefs and tumour. —
Both had healed, and I did not expc6t to feel any thing
more from them. — 1 tried this again with two dofes of ni-
trous oxide — The yellow halo round one wound changed
to crimfon, and there was fo much flinging and fwelling
that I feared fuppuration. — Abforption here was rapid.
( 547 )
fad very capable, I apprehend, of a pneumato*
logical interpretation.
Time by my feelings has always appeared
longer than by a watch.
I thought of trying to obferve whether while
I alternately breathed quantities of nitrous oxide
and oxygene gas and common air, I could ob-
ferve any difference in the operation of a blifter
beginning to bite the fkin. It would be of
confequence to afcertain the efFefl of regulating
by compreffion the flow of blood, while fiimu-
lants of various kinds (and heated bodies among
the reft) were applied to or near the extremi-
ties— becaufe in erifipelas and various inflam-
matory afi^edlions, a ready and pleafant cure
might be effe^led by partial compreflion of the
arteries going to the difeafed part ; and a great
improvement in practice thus obtained.
But I fliould run into an endlefs digreflSon,
were I to enumerate poflible phyfiological ex-
periments with artificial airs, or to fpeculate on
the mechanical improvement of medicine, which
at prefent as far as mechanical means of aff'efl-.
( 548 ) •
ing the living fyftem are concerned, is with us
in a ftate that would almoft difgrace a nation of
favages.
IV. Conclusion.
From the fa6ts detailed in the preceding
pages, it appears that the imniediate efFedts of
nitrous oxide upon the living fyftem, are analo-
gous to thofe of difFufible ftimuli. Both in-
creafe the force of circulation, produce plea-
furable feeling, alter the condition of the organs
of fenfation, and in their moft extenfive adlion
deftroy life.
In the mode of operation of nitrous oxide
and difFufible flimuli, confiderable differences
however, exifl.
DifFufible flimuli a6l immediately on the
mufcular and nervous fibre. Nitrous oxide
operates upon them only by producing peculiar
changes in the compofition of the blood.
DifFufible flimuli afled that part of the fyflem
( 549 )
moft powerfully to which they are applied, and
adl on the whole only by means of its fympathy
with that part. Nitrous oxide in combination
with the blood, is univerfal in its application
and aflion.
We know very little of the nature of excite-
ment ; as however, life depends immediately on
certain changes effefled in the blood i '3 refpi-
ration, and ultimately on the fupply of certain
nutritive matter by the lymphatics ; it is rea-
fonable to conclude, that during the adlion of
Simulating fubfianoes, from the increafed force
of circulation, not only more oxygene and
perhaps nitrogene mud be combined with the
blood in refpiration,* but likewife more fluid
nutritive matter fupplied to it in circulation.
* See Dr. Beddoes's Corfjideratmis, fart 1 . page 26, His
obfervations in the note in the laft fedion, will likewife
apply here. — Is not healthy living a6^ion dependant upon
a certain equilibrium between the principles fupplied to the
blood by the pulmonary veins from refpiration and by the
lymphatics from abforption ? Does not fenlibility more
immediately depend upon refpiration ? Deprive an animal
under ftimulation, of air, and it inftantly dies j probably
( 560 )
By this oxygene and nutritive matter excita-
bility may be kept up : and exhauftion confe-
quent to excitement only produced, in confe-
quence of a deficiency of fome of the nutritive
principles, which are fupplied by abforption.
When nitrous oxide is breathed, nitrogene
(a principle under common circumllances chiefly
carried into the blood by the abforbents in fluid
compounds) is fupplied in refpiration ; a greater
quantity of oxygene is combined with the blood
than in common refpiration, whilfl: lefs carbonic
acid and probably lefs water are evolved.
Hence a fmaller quantity of nutritive matter
IS probably required from the abforbents during
the excitement from nitrous oxide, than during
the operation of flimulants ; and in confequence,
exhauftion rom the expenditure of nutritive
matter more feldom occafioned.
if abforption could be prevented, it would Hkewife fpeedily
die. It would be curious to try whether intoxication from
fermented liquors cannot be prevented by breathing
during their operation, an atmofphere deprived of part of
its oxygene.
( 551 )
Since Rcfearch III. has been printed, I have
endeavoured to afcertain the quantities of nitro-
gene produced when nitrous oxide is refpired
for a confiderablc time.. In one experiment,
when I breathed about four quarts of gas in a
glafs bell over impregnated water for near a
minute, it wasdiminifhed to about two quarts;
and the refiduum extinguiOied flame.
Now the experiments in Refearch 11. prove
that when nitrous oxide is decompofed by com-
buflible bodies, the quantity of nitrogene
evolved is rather greater in volume than the
pre-exifting nitrous oxide. Hence much of
the nitrogene taken into the (yflem during the
refpiration of nitrous oxide, mud be either
carried into new combinations, or given out
by the capillary veflels through the fkin.
It would be curious to afcertain whether the
quantity of ammoniac in the faline matters
held in folution by the fecreted fluids is
increafed after the refpiration of nitrous oxide.
Experiments made upon the confumption of
nitrous oxide mingled with atmofpheric air
( 552 )
by the fmaller animals, would go far to deter-
mine whether any nitrogene is given out
through the fkin.
The various efFecSls of nitrous oxide upon
different individuals and upon the fame indi-
viduals at diiFerent times, prove that its powers
are capable of being modified both by the pecu-
liar condition of organs, and by the fiale of
general feeling.
Reafoning from common phaenomena of fenfa-
tion, particularly thofe relating to heat, it is proba-
blethatpleafurable feeling is uniformly conne61ed
with a moderate increafe of nervous ad^ion ; and
that this increafe when carried to certain limits,
produces mixed emotion or fublime plealure ;
and beyond thofe limits occafions abfolute pain.
Comparing the fads in the laft divifion, it
is likely that individuals pofleffed of high
health and little fenfibility, will generally be
lefs pleafurably affected by nitrous oxide than
fuch as have more fenfibility, in whom the
emotions will fometimes To far enter the limits
( 553 )
of pain as to become lublime ;* whilft tbe
nervous a6lion in fnch as have exquifite lenli-
bility, will be fo much increafed as often
to produce difagreeable feeling.
Modification of the powers of nitrous oxide
by mixture of the gas with oxygene or common
air, will probably enable the mod delicately
feniible to refpire it without danger, and even
with pleafurable efFc6ls : heretofore it has been
adminiftered to fuch only in its pure form or
mingled with finall quantities of atmofpheric
air, and in its pure form even the mod robull
are unable to refpire it with fafety for more than
five minutes.
The mufcular a^iions-f* fometimes conne6i£d
* Sublime emotion with regard to natural obje6ls, is
generally produced by the connexion of the pleafure of
beauty with the paffion of fear.
f The immortal Hartley has demonflrated that all our
motions are originally automatic, and generally produced
by the adion of tangible things on the mufcular fibre.
The common aftions of adults may be diflinguidied into
two kinds 3 voluntary adions, and mixed automatic a6lions.
The firft are produced by ideas, or by ideas conne6ted with
pallions. The fecond by impreflion, or by pleafure and pain.
( 554 )
with the feelings produced by nitrous oxide, feenx
to depend in a great meafure upon the par-
ticular habits of the individual ; they will ufually
be of that kind which is produced either by
common pleafurable feelings or ftrong emotions.
Hyfterical affedlion isoccafioned by nitrous ox-
ide, probably only in confequence of the ftrong
emotion produced, which deftroys the power of
the will, and calls up feries of automatic motions
formerly connected with a variety of lefs powerful
but fimilar feelings.
The quicknefs of the operation of nitrous
oxide, will probably render it ufeful in cafes of
extreme debility produced by deficiency of
In voluntary a6lion, regular affociations of ideas and
mufcular motions exift : as when a chemift performs a pre-
conceived experiment.
In mixed automatic a6tionSj the fimple motions produced
by imprcflion are conne6ted with feries of motions formerly
voluntary, but now produced without the intervention of
ideas: as when a pcrfon accuftomed to play on the harpfi-
chord, from accidentally ftrikiag a key, is induced to per-
form theferies of motions which produce a wcll-remembercd
tune.
Evidently the mufcular anions produced by nitrous
oxide are mixed automatic motions.
{ 555 )
common exciting powers. Perhaps it may be
advantageoufl)' applied mingled with oxygene
or common air, to the recovery ofperfons appa-
rently dead from fufFocation by drowing or
hanging.
The only difeafes in which nitrous oxide has
been hitherto employed, are thofe of defficient
fenfibility. — An account of its agency in para-
lytic afFedlions, will be fpcedily publifhed by
Dr. Beddoes.
As by its immediate operation the tone of the
irritable fibre is increafed, and as exhauftion
rarely follows the violent mufcular motions
fometimes produced by it, it is not unreafona-
ble to expedl advantages from it in cafes of
fimple mufcular debility.
The apparent general tranfiency of its opera-
tion in the pure form in fingle dofes has been
confidered as offering arguments againfi; its
power of producing lafiing changes in the con-
ftitution. It will, however, be eaf)Mo keep up
excitement of different degrees of intenfity for a
great length of time, either by adminillering
( 556 )
the unmingled gas in rapid fuccefiive dofes, or
by preferving a permanent atmofpherc, con-
taining different proportions of nitrous oxide
and common air, by means of a breathing cham-
ber.* That fingle dofes neverthelefs, are capable
of producing permanent effcdis in fomeconfli-
tutions, is evident, as well from the hyderical
cafes as from fome of the details — particularly
that of Mr. M. M. Coates.
As nitrous oxide in its extensive operation
appears capable of deftroying phyfical pain, it
may probably be ufed with advantage during
turgical operations in which no great efFufion
of blood takes place.
From the ftrong inclination of thofe who have
been pleafantly affected by the gas to refpire it
again^ it is evident, that the pleafure produced,
is not lod, but that it mingles with the mafs of
feelings, and becomes intclledlual pleafure, or
hope. The defire of fome individuals acquainted
with the pleafures of nitrous oxide for the gas
has been often fo ftrong as to induce them to
• See R. IV. Div. I. page 478.
( 557 )
breathe with eagernefs, the air remaining in the
bags after the refpiration of others.
As hydrocarbonate adis as a fedative,^ and
diniinifhes living aflion as rapidly as nitrous
oxide increafes it, on the common theory of
excitability:}: it would follow, that by differently
modifying the atmofphere by means of this gas
and nitrous oxide, we fhould be in polTeffion
of a regular feries of exciting and depreffing*
powers applicable to every deviation of the con-
ftitution from health : but the common theory
t R. IV. Div. I. page 46;.
X That of Brown modified by his difciples.
* Suppofing the increafc or diminution of living a(5^ioa
when produced by different agents, uniform, fimilar and
differing only in degree j it would follow^ that certain
mixtures of hydrocarbonate and nitrous oxide, or hydro-
gene and nitrous oxide, ought to be capable of fupporting
the life of animals for a much longer time than pure nitrous
oxide. From the experiments in Ref. III. Div. T. it appears
however, that this is not the cafe.
It would feem, that in life, a variety of different cor-
pufcular changes are capable of producing phaenomena
apparently (imilar j fo that in the fcience of living a6tion,
we are incapable of reafoning concerning caufes from effeds,
( 558 )
of excitability is moil probably founded on a
falfe general i fat ion. The modifications of dif-
eafed adion may be infinite and fpecific in
different organs ; and hence out of the power
of agents operating on the whole of the
fyftem.
Whenever we attempt to combine our fcat-
tercd phyfiological fa6ls, we are flopped by the
want of numerous intermediate analogies ; and
fo loofely connected or fo independant of each
other, are the different feries of phacnomena,
that we are rarely able to make probable con-
jeflures, much lefs certain predi<51ions concern-
ing tbe refults of new experiments.
An immenfe mafsof pneumatological, chemi-
cal, and medical information mufl be collected,
before we (hall be able to operate with certainty,
on the human conftitution.
Pneumatic chemiflry in its application to
medicine, is an art in infancy, weak, almofl
ufelefs, but apparently poffefTcd of capabilities
of improvement. To be rendered flrong and
mature, ihc mufl be nourifhed by fadls.
( 559 )
ilrengthened by exercife, and cautiouflydiredled
in the application of her powers by rational
fcepticifm.
APPENDIX.
No. I.
EjfeBs of Nitrous Oxide on Vegetation.
In July 17gy, I introduced two I'mall plants
of fpurge into nitrous oxide, in contac^l with a
little water over mercury ; after remaining in
it two days, they preferved their healthy ap-
pearance, and I could not perceive that any gas
had been abforbed. I was prevented by an
accident, from keeping them longer in the
gas.
K fmall plant of mint introduced into nitrous
oxide and expofed to light, in three days be-
came dark olive and fpotted with brown ; and
in about fix days was quite dead. — Another
fimilar plant, kept in the dark in nitrous oxidCj
M m
( 562 )
did not alter in color for five days, and at the
end of feven days, was only a little yellower
than before. I could not afcertain whether any
gas had been abforbed.
I introduced into nitrous oxide through
water, a healthy budding rofe, thinking ihat
its colors might be rendered brighter by the
gas. I was difappointed, it very fpcedily faded
and died ; poffibly injured by the folution of
nitrous oxide in water.
Of two rows of peas juft appearing above
ground; I watered one with folution of nitrous
oxide in water, and the other with common
water daily, for a fortnight. At the end of this
time, I could perceive no difference in their
growth, and afterwards they continued to grow
equally faft.
I introduced through water into fix phials,
one of which contained hydrogene, one oxy-
gene, one common air, one hydrocarbonate,
one carbonic acid, and one nitrous oxide, fix
fimilar plants of mint, their roots being in
(563 )
contact with water and their leaves expofed to
light.
The plant in carbonic acid began to fade in
lefs than two days, and in four was dead.
That in hydrogene died in lefs than five days ;
that in nitrous oxide did not fade much for the
firll two days, but on the third, drooped very
much, and was dead at the fame time as that in
hydrogene. The plant in oxygene for the firft
four days, looked flourifhing and was certainly
of a finer green than before, gradually however,
its leaves became fpotted with black and drop-
ped off one by one, till at the end often days
they had all difappeared. At this time the
plant in common air looked iickly and yellow,
whilft that in hydrocarbonale was greener and
more flourifhing than ever.
I have detailed thefe experiments not on
account of any important conclulions that may
be drawn from them ; but with a view of in-
ducing others to repeat them, and to examine
the changes efFe<5^ed in the gases. If it fhould
be found by future experiments, that hydrocar-
( 564 )
bonate generally increafed vegetation, it would
throw fome light upon the ufe of manures,
containing putrefying animal and vegetable
fubflances, from which this gas is perpetually
evolved.
The chemiftry of vegetation though imme-
diately connedied with agriculture, the art on
which we depend for fubfiftcnce, has been but
little inveftigated. The difcoveries of Prietlley
and Ingenhoufz, feem to prove that it is within
the reach of our inftruments of experiment.
No. 11.
APPROXIMATIONS
TO THB
Composition and Weight of the aeriform
COMBINATIONS of NITROGENE.
At temperature dS*^, and atmofpheric preflure 30.
1(50 Cubic In.
grains
Nitrogene
Oxygene
Nitrogene
30.04
c
Oxygenc
35.06
T3
6
o
Atmofpher.air
31.10
73.00
27.00
*->
0
1
5
Nitrous oxide
Nitrous gas
Nitric acid
50.20
34.26
76.00
(U o
00
bfl
63.30
44.05
29.50
36.70
' 55.95
70.50
Nitrogene] Hydrogenej
*
8
2
Ammoniac
18.05
80.00
20.00
-G
( 567 )
No. III.
Additional Ohfervat'wns.
a. In Ref. ifl. Div. IV. Se^. III. in theana-
lyfis of nitrous gas by pyrophorus, as no abforp-
tion took place when the refidiial nitrogcne was
expofed to water, I inferred that if any carbonic
acid was formed it was in quantity fo minule^
as to be unworthy of notice. A few day^ ago,
I connpleatly decompofed a quantity of nitrous
gas by pyrophorus, when the refidual nitrogene
was expofed to folution offlrontian, the fluid
became flightly clouded ; but no perceptible
abforption took place.
h. If there was the leaft probability in any of
Dr. Girtanner's fpeculations on the compofiiion
of Azote,* the experiments on the e:f haufted
capacity :}: of the lungs in Refill, might be
fiippofed inconclulive. But there appears to
* Annales de Chimie, 100 ^ and Mr. Tillochs Phil.
Magazine. 24.
\ 1 regret much that I could not procure Dr. Menzies's
obfervations on Refpiration, while I was making the ex-
periments on the capacity of the lungs : they would proba-
bly have faved me forae labor.
( 567 )
be no more reafon for iuppofing that hydro-
gene is converted into nitrogene by refpiration,
than for fuppofing that it is converted into
water, carbonic acid or oxygene ; for all thefe
produdls are evolved when that gas is refpired.
From the comparifon of Exp. 1 with Exp. 3,
Ref. iii. Div. ii. Sec. 4, it is aimoft demoaftra-
ted that no afcertainable change is efFecSled in
hydrogene by refpiration. The experiment of the
accurate Scheele in which hydrogene after being
refpired thirty times in a bladder wholly loft its
inflammability, may be eafily accounted for from
its mixture with the refidual gafesof the lungs.
About a fortnight ago, I refpired, after forced
voluntary exhauftion of my lungs^ my nofe
being accurately clofed, three quarts of hydro-
gene in a filk bag, at four intervals, for near
five minutes. After this it was highly inflam*
mable, and burnt with a greenifh white flame
in contadi with the atmofphere ; but was not
jfb explofive as before.''^
* If loofely combined carbon exifts in venous blood,
hydrogene may probably ditrolve a portion of it when
( 568 )
e. From what we have lately heard of the curious
experiments of Mr. Volta and Mr. Carlifle, it is
very probable that the converfion of nitrous gas
into nitrous oxide when expofed to wetted zinc,
copper and tin, in contadl with mercury, as
defcribed in Ref. I. Div. V. may in fome mea-
fure depend on the adlion of the galvanic fluid.
Whilfi: I was engaged in the ex|)eriments on this
converfion, Dr. Bcddoes ^ mentioned to mc
fome curious fa61s noticed by Humboldt and
Ritter, relating to the oxydation of metals by
the decompofition of water, which induced me
lefpired and become ilightly carbonated. At leaft there
is as much probability in the fappofition that carbon in
loofe affinity may combine with hydrogene at 980 as that
it may combine with oxygene.
* Dr. Beddoes has iince favoured me with the following
account of tbefe fa(5ts.
'' Mr. Humboldt (ueber die gereizte Fafer I. 473, 17.Q7)
quotes part of a letter from Dr, Afh, in which it is faid
that if txvo finely poUPied plates of homogeveom zinc he mois-
tened and laid together ^ little cjfc3 foUoius — hut if ■z.inc and
Jilver he tried in the fame ivay, the 'U)holc fiirfacc of the
filver ivill he covered ivith oxydated zinc. Lead and quick-
Jilver aH as poivcrfully on each other, and fo do iron and
( 569 )
to examine the phscnomena with more atten-
tion than I (hould have otherwife done. — I re^
colle6l obferving that fome of the wetted zinc
copper. — Mr. Humboldt (p. 474) fays that, in repeating this
experiment, he faw air-bubbles afcend, which he fuppoies
to have been hydrogene gas from the decomporition of
water — When he placed zinc fimply on moift glafs, the
fame phaenomena took place, but more llowly and later.
The quantity of oxyd of zinc upon the glafs alone was in
20 hours to that on the filver as one to three.
In a very ingenious but obfcurely written traiSt
by Mr. Ritter, entitled, E'vidence that the galvanic
adion exifts in organic nature, 81/0. Jena, 1800 — The
author obferves, that the care of Dr. Afh and Mr. Hum-
boldt that the metals fliould touch each other in as
many points as poffible was fuperfliious, even if we could
grant that two metallic plates might be made by polifliing,
to touch in a number of points. To fliew that it was fuffi-
cient if by touching in one point only they fhould form a
compleat galvanic circle, he dropped a fingledropof diiiilled
water upon the bull of a large lilver coin. A piece of pure
zinc was placed with its one end on the edge of the coin,
while the other was fiipported by a bit of glafs. The drop
of water was neither in conta6t with the glafs nor with the
point at which the metals touched. I'he mateiinls were
left in this fituation for four hours at the temperature of
680. On taking them apart, the water had become quite
milky and had half difappeared j and Mr. Ritter acluiilly
feparated a quastity of white oxide that h:id been produc^d
in the experiment.
The pieces of metal were cleaned and laid together in
(570)
filings in nitrous gas on the fide of the jar not
in contadl with the fiirface of mercury, were
very flowly oxydated. Whilft on the furface
of the mercury where fmall globules of that
fubftance were mingled with the filings of zinc,
the decompofition went on much more rapidly;
the fame manner, only that now a piece of paper was puc
between the metals at their former point of contad. In
four hours firft, and afterwards in ten, a faint ring of oxide
only had been produced of which the quantity could not
be eftimated, nor could it be feparated. In this cafe, the
zinc bad fcarce loft any thing of its fplendourj in the
former it had been corroded. In many repetitions of the
experiment, he found that far more oxide was formed when
the metals touched, than when they were feparated to the
flighteft diftance by an infolating body, even air.
On expofing thefe apparatufes with fomewhat more wa-
ter to a confiderable heat for four minutes, the water in the
interrupted circle continued quite clear, while that in the
other had become milk-white.
The fame phaenomena were prefented by other pairs of
metals in a degree proportional to their galvanic a6iivity ;
viz. by zinc and molybdaena, zinc and bifmuth, zinc and
copper, as alfo with tin and filver, tin and molybdaena,
and lead and lilver. The experiment with tin was parti-
cularly decilive, for when in conta6l with no other metal
:t was fcarcely at all oxydated by water, though oxydatiou
took place when tin was brought into contact with lilver.
( 571 )
poffibly through the medium of the moiftare,
a feries of galvanic circles were formed.
d. In Ref. II. Div. I. it is Hated, that nitrous
oxideduringits folution by common vvater,expeis
about -g of atmofpheric air the volume of the
water being unity.
and both were conne6led at the other end by a drop of
water — What therefore took place in Dr. Alh's experi-
ment, arofe from an aggregation of galvanic circles of
different forms.
By the foregoing experiments, concludes Mr. Ritter,
which though capable of the moft various modifications,
uniformly coincide in their main refult, it is abundantly
proved that galvanic circles can he forrued of merely inorganic
bodies, hy ivbofe completion there is produced an a^ton ivhich
ceafes ivhen the circle is opened. The manner in which this
has been fhewn, proves alfo that this adiion can cffcdu-
ate fenjibh modifications in organic bodies \ and the procefs
by which thefe modifications have been cifc61ed, made
it evident that they %vere not confequences of a momentary
adion of the circle, hut of an action that is kept up ivhile the
circle remains entire ) for the procefs which brought this
action under the cognizance of the fenfes went on, while
the circle was unbroken, and its figure not brought back
to that of a Une,
It is fcarce necefiar)' to obferve that the experiments
here quoted, arc far from being the only ones on which
the above conclufions reft." T, 11
( 572 )
From the delicate experiments of Dr. Pear
Ion, on thepaflage of the e]e61ric fpark through
water, it appears however probable, that much
more than -^ of atmofpheric air is fometimes
held in folution by that fluid,* poffibly the
whole of the air is not expelled by nitrous oxide,
owing to fome unknown law of faturation by
which an equilibrium of affinity is produced,
forming a triple compound.
■* Poffibly a ratio exists between the folubility of gafes
ID water, and the folubility of water in gafes. It is proba-
ble from Mr. Wra. Henry's curious experiments on the
muriatic acid, that the abfolute quantity of water in many
gafes, may be afcertained by means of its decompofition by
the ele6iric fpark.
( 573 )
No, IV.
DESCRIPTION OF A
MERCURIAL AIR-HOLDER,
Suggefted by an infpeftion of Mr. Watt's Machine for
containing Factitious Airs,
By WILLIAM CLAYFIELD.
Oeveral modes of counterafling the prefTure
of a decreaiing column of mercury having been
thought of in conjunction with Mr. W. Cox, the
following was at laft adopted as the mofl
fimple and efFedlual.
Plate 1 Fig. ], reprefents a fedlion of the
m^achine, which confifts of a ftrong glafs cylin-
der A cemented to one of the fame kind B,
fitted to the folid block C, into which the glafs
tube D is cemented for conveying air into the
moveable receiver E.
The brafs axis F, Fig. 2, having a double
bearing at a^ a, is terminated at one end by the
wheel G, the circumference of which is equal
to the depth of the receiver, fo that it may be
drawn to the furface of the mercury by the cord
h in one revolution ; to the other end is fitted
( 574)
the wheel H, over which the balance cord r run?
in an oppofite direction in the tpiral groove f,
a front view of the wheel H is (hewn at Fig. 3.
Having loaded the receiver with the weight
I, fojnething heavier than may be necelTary
to force it through the mercury, it is balanced
by 4 he fmall weight K, which hangs from that
part ofthe fpiral where the radius is equal to that
of the wheel G, from this point the radius of the?
fpiral mult be increafed in fuch proportion, that
in every part of its circuit, the weight K may
be an exacl coanterpoife to the air- holder. In
this way, fo little friction will be produced,
that merely plunging the lower orifice of the
tube D under mercury contained in the fraall
veflel L. will be fufficient to overcome every
refiftancc, and to force the gas difcharged from
the beak of a retort into the receiver, where
whatever may be its quantit}% it will be fubjecled
to a prefTure exa<9Iy correfponding to that of
the atmolphere. The edge ofthe wheel H being
graduated, the balance cord c may be made to
indicate its volume.
-Should it at any time be neceffary to reduce
( 575 )
the prefTure to the medium flandard of the
barometer, it may eafily be done by graduating
the lower end of the tube D, and adding to the
weights I or K, as may be found necefTary ; the
furface of the mercury in the tube pointing out
the increafe or diminution.
The concavity at the top of the internal
cylinder is intended to contain any liquid it
may be thought proper to expofe to the ad^ion
of the gas.
The upper orifice /, with its ground-ftoppcr,
is particularly ufeful in conveying air from the
retort g, with its curved neck, into the receiver,
without its paffing through the tube D. In all
cafes wherea rapid extrication o! gas is expedled
the retort^, (hould be firmly luted to the ori-
fice, and the weight I, removed from the top
of the receiver, this by diminidiing the pref-
fure, will admit the gas to expand freely in the
air-holder at the inftant of its formation, and
prevent an explofion of the veflels. The fame
caution muft beobferved whenever any inflam-
mation of gas is produced by the eledlric fpark.
The air may be readily transferred through
water or even mercury by the tube >^, Fig. i .
( 570 )
To prevent an abforption of mercury in cafe
of a condenfation taking place in the retort
made ufe of for generating air, Mr. Davy has
applied the ftop-cock /, to which the neck is
firmly luted. This ftop-cock is likewife of great
fervice in faturating water with acid or alkaline
gafes, which may be effedled by luting one
end of the tube ^ to the ftop-cock, and plung-
ing the other into the flu.d in the fmall veftel /,
cemented at top, and terminating in the bent
funnel ;;z — the tube h having been previoufly
removed, and the lower orifice of the tube D
either funk to a confiderable depth in mercury,
or clofed with a ground ftopper. The bend of
the funnel w, may be accurately clofed by the
introdudlion of a few lines of mercury.
The application of the ftop-cock «, has
enabled Mr. Davy to perform fome experiments
on refpiration with confiderable accuracy.
Note. This apparatus was iirft defcribed in the third part
of Dr. Beddoes's Conliderations ; its relation to Mr. Davy's
experiments with the improvements it has lately received,
may probably be deemed fufficient to cxcufe the re-printing
it. — The weight I. Fig. 2, having been omitted in the
plate, the reader must fupply the deficiency,
W • \^»
^e^msas^mmmiM
PROPOSAL
FOE
THE PRESERVATiOX
ACCIDENTAL OBSERVATIONS
MEDICINE.
iN^ tioiei bejoad the reach of hifiorj, the medkiaal
application cf fabSaDces cooM hare ariien from do
other foarce than acddeat. AoK^ng artides of the ma-
teria medica cf known origin, we are indebted to acci-
dent for ibme cf the rooft predons.
Accident is CTcry day prefcnting to different individnals
the fpct^de of pbaeooGiena, arifing fhrn nnconmica
qaiotities cf drugs on the one hand, and (Xi the otho*,
from nncocamoD conditions of the ijfteni, wbone ordlnaiy
powers only have been knowingly or recently ap|^ed.
What is faid of drags may be extoided to natural awaits
and mental atife^ons.
From coDFerfatioD with a var.eiy both of medical prso
titioners and cnprofeliiaGal obienrcrs. the aatbor of this
propofal 15 perfuaded that fcch aotheotic occtnTBoces
only, as hare prefeated tberale'lTes to perfons now living
would, if ihey could be brought together, compole a body
of fact, fo inftra^ve to the pbilofcpher, sec ufefiil to tl^
pbyfidan, that he deipairs cf niidiEg 2 ttnn \^onhy 1^
diarafteriaeit.
( 578 )
In fome cafes, the influence of unfufpe6led poweis would
be detected. In others, refources available to the purpofe
of relloring health in defperate fituations would be
directly prefcnted, or could be detected by a fhort and eafy
procefs of reafoning. Some anomalous obfervations, by
ihewing the abfence or agency of conteiied caufes, woul^
perform the office oi experhnenta cruets — Unufual affeAions
occur of which an exa6t account would be among the means
of removing from phyfic its opprobrious uncertainty: for ihis
uncertainty frequently depends upon our inability to diftin-
guifti the fubtler differences in cafes which refenibie each
other in their grolfer features.
No ttriking fa6t can be accurately flated, in co!ljun6lion
with its antecedent and concomitant circumftances, without
improving our acquaintance with human nature. Our
acquifltions in this moft important branch of knowledge^
may be compared to a number of broken feries, of which
we have not always more than one or two members. But
every new accelTion bids fair to fill up fome deficiency j
and a large fupply would contribute towards conne6ting
feries apparently independent, and working up the whole
into one grand all-comprehending chain.
There are complaints, and thofe by far too frequent,
where no known procefs has a claim to the title oi remedial.
Here the whole chance of prcfervation depends on th'e phy-
lician's capacity for bringing together fads that have
heretofore flood remote. But no power of combination
can avail where there are no ideas to combine.
Every new obfervation therefore, may be confidered as a
ftandard trunk, fending forth analogies as fo many brancheg
crowned with bloffoms, fome of which cannot fail to be
fucceeded by falutary fruits. And were it not abfurd to
e;;tend the illuftrMion of fo plain a point, it might be added^
( 579 )
that when by the continual interpofitlon of new trunks,
the branches are brought near together, the produce of each
will be ennobled by the a6tion of their refpe€i:ive principles
of fecundation.
"Whenever the author has been able to obtain certain
information concerning any unufual appearance in animal
nature, it has been his cuftom to preferve it ; and among
his papers he has memorandums which prove that to
our prefent eircumfcribed ideas concerning the dofe
of medicines may be fometimes imputed failures in
pradice j that certain (igns are not to be taken in the
received fignification j and that manv meafures are adopted
or omitted to the detriment of invalids, becaufe it is affumed
that circumftances are neceflarily connefted which may
exift feparately, or that one given natural operation is incon-
liftent with another, to which it may really be fynchronous
or next in order.
Arduous obfervation of the daily dates of the hu-
man microcofm will be the unfailing confequence of atten-
tion to its ftriking phaenomena. Such is the progrefs of
curiofity. Such the origin of all the fciences. The more
uniformly clear the iky under which they tended their
flocks, the lets likely were the fliepherds of Chaldaea, to
found the fcience of the ftars. And however the difpofition
to ftudy aftronomy might have been ftrengthened by the
coincidence between the heliacal riling of Sirius and the
ovei-flowing of the Nile, it muft, I conceive, have been
awakened by the afped of meteors and eclipfes.
Whatever minute and authentic information this im-
perfc6t ftatement may produce, as foon as it {hall amount
to a certain mafs, the author will prefent it to the public
arranged. He flatters himfelf that no correfpondent will eke
out by fuppofition the dcfcA of genuine obfervation, without
( 580 )
cleatly diftinguifhing the one from the other. He ftill m6te
cJonfidently hopes that none will be inftigated by this adver-
tiferaent to exercife his invention in the manner of Pfal-
manafar and Chatterton. Whether any literary forgery
can be innocent is queftioned— but a forged medical report
is a drawn dagger which the arm of a credulous phvfician
may any day plunge into the heart of his defence-
lefs patient. The author has heard fome inconfiderate
wits avow, that they have tranfmitted to the venders of
quack medicines imaginary cures, attefted by fidtitious
Signatures ; and it is not without apprehenfion from the
propeniity of men to difplay ingenuity and to relate
wonders that he announces the prefent delign. But
he fhall be on his guard, and hopes to baffle attempts at
impolition.
THOMAS BEDDOES-
Rodney-Place, Clifton, June 1800.
END.
ERRATA.
Page 19 line 15 for is read are
— 35—7 — for pritictple redid principles
— 42 — 11 — for take read takes
— 68 Table 5 — for 5,88 read 15,88
_ 04. _ 4 — for 1 i read -i
12 12
— gs — 4 — for 37 read 30,7
— 96 — 3 — for 38 read 1
38
— 105 — 9 — for exa&itude read exaiftiefs
— 129 — 21 — for 41 read 4,1
— 132 — 4 — for into read in
>— 143 — 13 — for 25 read .25
— ■■ 186 — 15 — for by read /row
— 208 laftline— for abJiraSied read attra^ed
— 238 — 5 — for gas read oxide
— 259 — 4 — for 12 read 2
— 283 — 4 — for /o/^ read /Vo«
— 315 — 14 — dele in
— » 4O9 — 15 — tot rejpiTatiun icad expiration
— 464 — 10 — for latter end read end
— 543 — 3 for exhalation read inhalation.
A few literal errors are left to the reader's corre£lion.
K. B. The term ignited is fometimes ufed to fignify any tem-
perature equal to or above a red heat, whether applied to folids,
fluids, or aeriform fubftances.
The reafons for the ufe of the terms nitrogene and nitrous
nxide, are given in Mr. NichoKou's Journal for January.
speedily will be Publisbed,
OBSERVATIONS on tke External and Internal Ufe of
NITROUS ACID.
Demonftrating its PERMANENT EFFICACY in
VENEREAL COMPLAINTS ;
And extending its ufe to other dangerous and painful
Difeafes.
COMMUNICATED
By various Praditioners in Europe and AsiA;,
TO
THOMAS BEDDOES, M. D.
Of the Publisher may be badj price is. 6d.
NOTICE Kjf OBSEKVATIONS
AT THE PNEUMATIC INSTITUTION,
By THOMAS BEDDOES, M. D.
This Notice contains fome trials of nitrous oxide by healthy perfons,
not in the prefcnt work, and fome cafes of palfy fuccelsCully treated
by that gas.
Printed by Biggs and Cottle, St. Augusti tit's Bad,
^
^
t>'
COUNT WAY LIBRARY OF MEDICINE
QD
181
Nl D31
RARE BOOKS DEPARTMENT
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